Thanks everyone for the support and suggestions. After discussing them with my friends, I'm going to do the following:
(1) I will ask the 2010 C5 seller if he will keep it for another month so I can save up the $600 to ship it to San Diego (we're buying furniture so cash flow got constricted
)
(2) meanwhile I will take the trashed 2016 C5 engine to my workshop in Descanso; disassemble it (I'll take pictures for you); and see what can be salvaged.
(3) when the 2010 C5 arrives, I will mix and match engine parts (eg 2016 sprag into 2010) to achieve a working engine.
(4) when I have enough money to buy the Hitchcocks stainless exhaust (est $200) I will match it with the 2010 C5 silencer and install the AT-200 UEGO to support the PC V air-fuel management and monitoring.
(5) if I get lucky and someone buys the Integra then I'll get a professional upgrade of the head assembly (eg Hitchcocks p/n 90273) and maybe even piston (eg Hitchcocks p/n 90225). I'll check with GHG, ace.cafe, et al before taking action in these areas.
(6) while waiting for the leprechauns to drop off the pot of gold, I'm going to stop wasting my time on foreign policy news and address fine-tuning details such as resurfacing the rotor and pads per Ducati Scotty, etc etc. Driving the Windstar is a motivator.
I understand and appreciate those who recommend keeping it stock and driving it appropriately. But that isn't me. The RE is like my Mustang; its tidy and "Ford-like" for the tech inspector but there isn't a single part I haven't touched. And while I keep it to 55mph, on open roads I use full throttle to get there and I ain't changing that.
In summary, this motorcycle is such a pleasure to ride and so well matched to my needs that I'm throwing the dice again.
Thanks all.