That sounds like a successful engine rebuild, Ben, it should be good for a couple of decades of home use, at least. So far as the mower rebuild/replacement is concerned, people post here fairly regularly that they have bought SB 45s at good prices, though not always in overall good condition. It seems to me that having now a top-grade engine ready to go, you would be able to buy a mower that had been neglected rather than abused, so it is relatively easy to fix the frame and cutting system. In particular, there are plenty of them out there that have never had the reel or bedknife ground. Some surface rust shouldn't matter, the important thing is that you should never need to replace the reel (which costs more than a second-hand SB45). The best approach though, it seems to me, is to get one of the old neglected machines that have sat in a wet shed for several decades, aren't running, and look awful - but have hardly been used. Amateur maintenance may have done terrible things to the engine, but that won't matter.
