Last spring I found a good, used L/U for my '75 Johnson 25hp, but it's starting to slip out of gear just like my old one did. I know the clutch dog needs to be replaced, but that and a new seal kit would make it a great performer again. This is only speculation though, since I haven't actually opened it up to check for sure. I've got my old one apart right now and am gonna order parts for it this week, so I thought I'd see if anyone was interested in having a good rebuilt L/U. I know it will fit most (if not all) 18-25hp (and maybe 35hp) OMC motors from at least '57-76. It comes with a short shaft and exhaust line. If anyone is interested I can post pics so you can compare it to yours.
I'll go through it and replace all the seals, clutch dog, impeller and any bushings that need it, then clean it up and slap some epoxy-based paint on it if someone is interested in buying it. Part will run $150ish, so I think $400 would be fair. If you're close to Conway I can even help install it. I don't know when I'd have time to test it out, but I'll buy it back if it doesn't perform to your expectations. If anyone is interested, shoot me a PM this week so I can open it up and make sure everything is in good shape before you commit and I order parts.