For several years I've been shopping for a Sunnen hone, and I scored a very nicely reconditioned one on Ebay a few days ago. Once my hands mend from the carpal tunnel surgery I just began yesterday, I'll be acquiring tooling a little at a time and building a recirculating system for honing oil. I'm also working on building a dedicated boring fixture to replace the compound rest on my lathe carriage so I can bore the Babbit material out of splash-oiler connecting rods. Between a precision boring tool adapted to the lathe spindle and the hone, I should be able to start supplying engine builders with insert-bearing rods.
I've found a source for bearing shells that cost a fraction of what the dedicated conversion items do, and they're much more available. Certain sizes of splash-oiler conversion bearings are getting almost impossible to find, even from people who claim they have them in stock!
Jerry