Terrible photo. I'd bet the switch assembly would mate up to the R65. Might need to do a little mod'ing of the wire harness and/or connectors, but might not. There's also the headlight dimmer switch and horn button.
What could possibly go wrong?

Just checked the A&S microfiche.
http://www.ascycles.com/illustrated_parts_catalog_main.aspxThe R100S and R65 switch assemblies look identical but have slightly different part numbers. Terminals appear to be the same. Ought to be OK for you, David. Price is sure cheap enough.
Monte