[Leica] Screw thread questions.

[Coresect <coresect@tin.it>]

So, I've been on the list for a couple of days and the community looks
interesting. I didn't expect so much politics but I can live with that.
Strange how almost everyone who stated that Peru topic is not suitable
for this list did so after putting forward their point of view :-)
On a more on topic note; Are there any good informative web pages where
I could find out more about my Leica?
>From what I can figure out it's a model IIIa (114886) but I'd like to
make sure. Hate to say it, but it was a present from a friend who knows
nothing about cameras. It had been sitting on a shelf for god knows how
many years and I told him he should at least dust it every now and then
(his kids played with it too...). So he gave it me, he must hate
dusting. I've put a film through it and it works, though the slower
speeds seem to be shot so I can only use speeds 1/60 and faster. I'm
happy it works, and I doubt I could afford a repair. I have other
cameras I work with, no Leicas unfortunately, but an interesting
colection nonetheless (from my first camera; a Zorki 4 through contax,
minolta and a kiev 88). Anyone know a repair shop in Rome for this kind
of Leica..? Would it be worth it? There are lots of talk about lenses,
what is compatible with mine and what isn't? Finally (sorry about the
long mail), everyone seems to be talking about the M series, are the
older Leicas On Topic on this list?
Thanks for your time,
Paul.