Mal, aside from not knowing the quality of the thread, we end up without the lateral rib that Briggs provided, to stabilise the mount and prevent fatigue damage from vibration in that plane. The rib is still in place on the other mount, and as long as the bolts are tight, the coil's laminated core is tying the two mounts together, transferring some load to that other rib, but it all looks fairly chancy to me.
I agree that for some really rare items, the sky is the limit on how much work you do to repair them. The poor unfortunate souls who maintain 1930s Bugattis face many awkward challenges, and regard long sessions on a milling machine as part of the fun of ownership, but they would not do it if they had a choice of picking up a complete engine in good condition for $10-20. (Actually some of them would refuse a new engine, since the numbers wouldn't match their provenance documents, but any un-numbered parts are a different story.)
