[mikethedruid]

Hi R.F. !
I read your latest post. Congratulations on all your work on this magnificent radio ! It got me thinking, and that got me hunting on the net. I found a few sites that might be of help or interest you you:
http://userpages.bright.net/~geary/fm/fmconverter.html

http://www.theradiofox.com/fm/fmconverter.html

https://antiqueradios.com/forums/viewtop...&p=2416131

https://antiqueradios.com/forums/viewtopic.php?t=147062

That last link has a link in it to a Russian site that has an old Popular Mechanics article on how to make a converter for the old to new FM bands. Hope you find them at least interesting, if not useful. And last, here is a link to download that Popular Mechanics article in case you feel like trying it, and one to another Popular Mechanics article from 1946 on a different converter you could build, They are both PDFs, so you can DL them if you want.
http://www.vacuumtubeera.net/FM-Converte...Device.pdf

http://www.vacuumtubeera.net/One-Tube%20...y-1946.pdf