Here is a pair of McCulloch 640 gear drives. They have say awhile and as you can see one sat on concrete and got magnesium cancer. I do not have any history on them but I will assure you they could tell a tale if they could speak.. The short story. They both turn over with compression, one needs a coil, recoil spring, bolts for the fan shroud and I am sure some other things. The other looks better but has serious magnesium rot as pictured. You truly need to use the two to build a good saw. One has the bow bar guide yet behind the gear but I am keeping that. You can easily swap some parts and build a darn good saw while having lots of parts left over. I think $300 for the pair plus real shipping is fair