Jmo, the block is the main thing of worth. The large (0.921) roller lifters and dog bones possibly can be used on a Toronado/400 E block. There was a thread about someone was going to try to use them. Not sure how it came out. One couldn't use much lift without oiling problem. I think Bill Travado use diesel lifters in a build.
The block should be worth $250 at a minimum, imo. Rocket Racing wants $5K for their big gunner block, so these peanut blocks (440 cubes) should be worth something. I have a couple just in case I live to be a 100. By then I should be getting to the end of my bucket list. Building one is on the list, somewhere.
Complete engine, I'd try $500. You can always go lower. Good luck.
The good, almost all the "heavy hitters" in Oldsmobile drag racing use/used diesel blocks. The bad, Oldsmobile racers are "dying" off without new blood coming in.
Imo, they are the ticket for a sturdy Oldsmobile race engine. Do it once and save time and money in the "long" run.