Sounds too inexpensive if it's a rebuild, that's a reasonable price for a used, not rebuilt trans. Especially with your return trans virtually unusable for core value.At todays parts prices even discounted you'll easily put $2,000 plus in parts in the trans. ALL 915's have a lot of miles on them and if you plan to upgrade an early box i.e. later, stronger hubs and new sliders, update 1st gear dogs, figuring an early 915, your looking at a LARGE bill. Heck look at the price of bearings.
Great points on the stubs, speedo etc. Tom74 911.