This one was pretty lame before - but tonight I got an idea for another stage in the "decoder ring" and while adding it, came up with the loop and finally an idea to obfuscate the remaining, still pretty obvious part. So I have what I think is a decent JAPH - I've seen more complex and/or well thought out ones of course, but I think I did a sufficient job of coming up with something that's not quite immediately obvious. Considering I generally suck at obfuscation :-)
I'm pretty content.
Makeshifts last the longest.