I'm not too familiar with the certain models or names of the cars. But I DO know that those ancient dinosaur AmCans, as you like to refer to them as, I can only say one thing; Gotta go!
I'm pretty certain that they've been rebuilt multiple times, but it is now time to cut the cord with those cars, get new more efficient shiny ones and put those old cars out to pasture. Hopefully, the new cars will have overhead bins like the ones featured on the Acela trains!
Also, I'll be so bloody glad when the much older dining / cafe cars are replaced! Hopefully, the new ones will have more room, seating wise. They ARE having new ones made, also in the shape of the Viewliner cars.
The Viewliners are a lot taller and should be able to accommodate overhead storage. You'll get some idea what their ultimate coach configuration is going to be when they finish rebuilding those few long out-of-service sleepers into coach prototypes. Those should be out there next year sometime for revenue tests, although obviously with only a few prototypes to go around it's luck-of-the-draw if you ever get to ride the inside of one.
Right now these are the single-levels they have on the roster that are up for retirement.
-- Amfleet I (built 1974-75; originally 492 units now 470+ with some in long-term storage). These are the corridor coaches. Up to 84 seats, with some being configured as cafe or business cars.
-- Amfleet II (built 1980-81; originally 150 units now 145). These are the LD coaches. 59 seats, some configured as dinettes. Only way to tell apart from an Amfleet I on the outside is the slightly larger windows.
-- Metroliner cab cars (built 1968-69 as Metroliner EMU's, converted to cab cars 1982-2007; originally 61 units now 17 with many stored or scrapped). These were the gov't-funded experimental high-speed EMU's for private Pennsylvania RR that were the first stab at an Acela-like HSR service on the NEC. So infamously unreliable and breakdown-prone they never moved at their rated speed and ended up setting back the cause for HSR in the U.S. by 30 years. Amtrak inherited these lemons upon its inception and retired them all from self-powered service in 1982. Since they have engineer's cabs at each end and coach seating they did work as push-pull cabs. They started using many of them for that purpose as-is...simply with the pantograph dropped, in later rebuilds fully demotorized as de facto Amfleet cabs. Budd had so many extra Metroliner shells lying around its factory after the original 100+ order was cut short by all the problems they were having that it developed the Amfleet coach as an excuse to use those last shells...and basically saved the company in the process because
as coaches they were basically the most reliable purchase anyone's made in the last 70 years. Impossible to tell a Metroliner apart from an Amfleet I except for the end cap with the engineer's cab.
-- Horizons (95 ordered, 95 in-service; built 1988-89). Some cafes and cafe/business configurations. These are "Comet"-class design, which is exactly the same as all of the MBTA's single-level coaches. Interior configured for corridor service more or less identical to an Amfleet I, but they have that harsh commuter rail lighting. Banished to Midwest and West because manual doors require conductor assistance, and they don't want that mixing on the NEC. Rough ride quality, and problems with stuck doors and plumbing on the toilets. Most of them being displaced by the Superliner corridor cars on-order for Chicago hub, so most of the Horizons will be put on reserve as a 'swing' fleet.
Of these the Metroliners are in most urgent need of replacement because of their age, small numbers, and fact that when Amtrak's more powerful next-gen diesel locomotives are delivered they'd really like to convert all non-LD, non-NE Regional trains to push-pull to save the expense of a second locomotive. Which means they need more cabs. Probably the first new Viewliner configuration they order next.
Horizons are being displaced by bi-levels and definitely aren't going to be appearing East except in cases of equipment shortages (e.g. Thanksgiving/Xmas travel extras) because the East Coasters would hate them even more than the Midwesterners do. So with most probably being stored they're easy to retire.
Amfleet II's go before the I's because they've been ridden into the ground on LD routes and are in much poorer condition. And there'll be less need for them overall when the Superliner III bi-levels get ordered and banish the II's to just the handful of LD routes operating out of New York or other low-clearance places.
I's are last because there's so many more of them to replace that they're better off purging the smaller numbers of the other 3 vehicle classes first. It's not like 500 units can just be pumped out overnight. Also, they will have more reserve units onhand when the Midwest corridor bi-levels are in-service, because Amfleet I's supplement the Horizons on many routes and even go out to California to deal with their car shortage. Those will all come home to East Coast to give the rest of the active fleet cushion and more shop time to safely increase their lifespan to the back end of the replacement order.
So, yes...you're going to have to put up with them on your NE Regional for another 10 years, unfortunately. But the upside is there'll be more of them coming back East when all these ongoing bi-level orders ease the car shortage. So in exchange for the 10-year wait you'll be getting a good 8 years of less-crowded Regionals with more cars available to run them. And they will get replaced. It just can't be overnight with them juggling such a fury of locomotive, bi-level, and single-level orders more or less 2 at a time for a decade straight. It's basically the most all-new passenger equipment anyone in this country has tried to order in that short a span of time in almost 100 years. So...can't quibble too much with the results. Especially when the replacements--Superliner/bi-level based or Viewliner/single-level based--are such battle-tested designs. We know it's going to be a high-quality product.