Hydraulic Ironworkers have pretty much taken over for the flywheel/mechanical type ironworkers. An ironworker is, to a large extent, dependent on condition of cutting edges on the shear and notcher (if fitted). It is also dependent, to a large extent on tooling. This consists of punches and dies for various sizes and shapes of holes.
As much can be spent on getting the needed punches and dies as on buying an old mechanical ironworker.
In their day, the mechanical ironworkers were widely used in structural steel fabrication, as well as plate steel fabricators such as boiler works and shipyards. I've used both mechanical and hydraulic ironworkers. The mechanical ironworkers, for their rating, weigh a good bit more and take up more space, than the equivalent rated hydraulic ironworkers. The major feature that distinguishes the two types of ironworkers is the fact that with the mechanical ironworker, when you hit that foot pedal, it's 'off to the races" with no stopping. Once the clutch goes in on the flywheel, the ironworker is going to run thru a complete cycle. With the hydraulic ironworkers, you can inch down the punches or shear and even when you hit the foot pedal it seems like a more controlled action.
On old mechanical ironworkers coming out of structural steel fabrication plants, there is no telling how much wear there is on the working parts aside from the shear and notcher. I've used Buffalo as well as Peddinghaus mechanical ironworkers. On the older one, you hear the spur gearing clanking along, sounding kind of loose. When you hit the pedal, the sheepsfoot (stripper plate) comes down to clamp the work and then the ram with the punch (or cutting edge) comes down. Plenty of men lost fingers to the sheepsfoot trying to line up punch marks or layout marks with punches or cutting edges. Once you hit that pedal, a mechanical ironworker is going to go thru its cycle without any stopping it. In my opinion, the hydraulic ironworkers are a safer machine, aside from lower first cost vs mechanical, and easier to setup and move around the shop.
It is quite rare nowadays to find working structural steel fabricators still using mechanical ironworkers. I would no think that old ironworker is worth much more than scrap.