Rob the pleasure was mine and your Flex sounded great.
The inspiration for the mod comes from
http://www.amwindow.org/tech/htm/ts940s.htm I believe you're right when you say this method can probably be applied to other rigs as well. I've been successful with the FT-847 and the FT-757GX. I've got an IC-706 and a FT-857 that I hope to experiment with one of these days. Yes I will make some notes on the mods and pass them along. 73 Phil