Yeah, collecting these things is not hard thing to fall into - I didn't mean to buy one, now I have two "poor man's Leica's"...hehehehe
I had the top cover off my 19 - I only ended up cleaning (qtip and rubbing alc) the parts that I could tell would not move when touched. I meant to do more, but got scared - after all, I thought,its better a little dim, than completely useless because some clutz (me!) tried to clean it and knocked it around a bit! It takes some practice, and finding something with a sharp line and colour demarcation is helpful, but other than that, its fairly non-problematic.
And the 19 takes no batteries! Its great. Soooo quiet. After buying these RF's I started referring to what happens when you shoot an SLR as "recoil"