I don't own LGs anymore, (sold my LGs and went to an Air Hammer about 7 years ago) but had both 25 and 50lb models in my shop for almost 20 years. I've overhauled/rebuilt 25-30 in my time. One thing that I always tell folks to look for is shims in the main bearing journals.....(between the base and caps that hold the main shaft). If shims are present, you're likely not going to have to re-pour the main bearings....just possibly remove a shim or two to tighten up the main bearings. Next most important thing is to check for any "slop" in the flywheel....there should be a LITTLE slop, which was intended to be "grease space" in the hammer(s). Excessive slop would mean either re-pouring the flywheel babbit, or you could do what I always did....have it machined and a bronze sleeve bearing pressed in (makes em run like a singer sewing machine)
If it's a "new style" hammer, it will have "dovetail" guides for the slide.....check to make sure there isn't excessive slop in those dovetails....and if there is...how much adjustment to the three bolts on each side have?
Finally, check the dies carefully.....if they are correct, they should be held in place with a tapered/square pin......if the dies are welding in (and I've seen a bunch that way), walk away from it! It's nearly impossible to get the dies out without cracking/breaking the casting their seated in.
As far as money goes.....if the hammer is in "ready to run" condition, with motor, switch, good dies and all, $2,500-$3,200 is a fair price. If it needs work.....well, it all depends on what it needs. I've paid as little as $300 for a 25LG that needed a rebuild, and I sold my 25 (after I had rebuilt) for $3,200.
