Hi happycat,
I'm familiar with Bliss presses as I work for a company that does a lot of stamping. I'm not sure how effective (or safe) if would be to use that type of press for forging. Those presses are REALLY dangerous even when used for their intended purpose.
The big problem with a mechanical type, full revolotion press is that once it's tripped there's no going back. It will either make a full revolution or lock up at the bottom. The problem is compounded by the fact that there is no room for varation of parts thickness at the bottom of the stroke. A few thousanths of an inch can mean the difference between making a complete revolution, lock-ing the press down, or (worse yet) ejecting shrapnel out towards the operator at Mach 2. If you do manage to lock the press down, sometimes you can get lucky and unstick it my reversing the leads on the motor. More often that not it will require a hydraulic jack, overhead hoist, or lift truck. I have even seen situations where the ram screw had to be cut with a torch to free the press up.
If you found a press with enough stroke, you might be able to devise a weigh on a slip shaft so it would operator similar to the little giant power hammers. This way it couldn't bottom out and cause all the problem mentioned above.
Another thing to think about is that those presses are notorious for "phantom" tripping when there really old and worn. That's not a good thing for something that you're going to be sticking your hands under. You might consider trying to locate a set of mechanical "pullbacks" to make sure your hands are out of the way.
Feel free to drop me an email if you have any questions. If I don't have the answer I may be able to point you in the right direction.
Take care and good luck,
Cecil
