I need help. I tried to get my flathead running this weekend. I bought the engine from a guy who said it was a running motor, but it had been sitting for several years. The motor turned over fine, but had three valves stuck in the open position. I was able to get them loose with the help of my good friend WD40 and some light tapping with a hammer. The valves are loose, but still don't have compression in two cylinders. So I pulled the heads and intake and noticed the valve springs were still compressed but the valves still moved freely. After inspecting the engine I noticed there are no visible cracks in the block. Also, it appears the motor has been rebuilt. There are a couple of small scores in two cylinders. Other than that everything looks good. It has one piston that has different markings on the top of it. That's why I believe it has been rebuilt. So my question is.....Are there any other choices besides rebuilding the whole engine? And what kind of cost am I looking at if I decide to rebuild it? Nothing crazy...just a good runner. I attached a few pics. Any suggestions would be great.