Going by the bottom photo, the unit has a decent paint-job with no rust spots showing through. Suggesting it has been cared for reasonably well, and might be in decent condition generally. In which case it would be a pity if it was just cut up!
As for what model it is… Not having an Alco S on a turntable to view from the camera angle shown I can't be sure, but it LOOKS as if the radiator is the short one used on S1/S3, not the longer one on S2/S4: somebody with a better eye than mine, or a photo collection that includes some taken from this angle, could confirm or refute this. The basic engine BLOCK is pretty much the same, and de-turbo-ing an S2's engine before reinstalling it in an S1 shouldn't have been beyond the abilities of Relco's shop.