It sounds good Mike, I have thought about one myself but for the amount of time I actually use a closed faced reel these days i've just stuck to the 501. I still have an original 506 but the drag is pretty dire and I have lost fish because of it's poor operation.
I've never used the drag on my Abu 506 anyway, I use it with the anti-reverse pawl removed (which is a very simple operation) and use the backwind for any fish that decides to pull back; which has always been a common mod amongst original 506 users back in the 60's and 70's
I use spools made for the 506M on my 506 which has chenille liners around the backs of them, which prevents finer lines from going behind the spools. The heaviest line that I use on my 506 is usually only around the 4lb mark anyway.
I still occasionally use my 506 if it gets a bit too blustery to use one of my pins and I'm trotting for chub roach and dace; although I don't think I'd be really happy using my 506 if I was trotting after bigger and more powerful fish like Barbel or Carp using heavier line, in which case I will tend to step up to a different reel altogether like one of my stradics or Diawa match reels
Keith