Once I get some tools, does it matter whether I start experimenting 
with clarinet or alto, tenor, or bari sax MPCs (these are what I have 
around the house)?

At the moment, I've been considering acquiring some Yamaha or Rico 
bari MPCs, even though they're plastic, since they're fairly 
inexpensive on eBay, and since I've been playing a bari fairly 
regularly, more so than anything else other than always going back to 
my alto, just for fun.

Or, would I be better off to start with some rubber MPCs?

Or does any of this matter, as long as I start measuring and working 
on some of what I have around?

It does not matter a lot where you start.  I think most beginners ruin 1-3
mouthpieces, so start with what you wont mind losing.

I started on a clarinet and could not get the table flat until it was way
overcut.  I then filed the sides and practiced on the facing curve.  Then I
hacked away at the chamber some.  Just getting a feel for each stage of the
work is what you need.  I was trying to make a playable piece, but I think
it would have been less stressfull if I just accepted the 1st one was
strictly for the feel of the tools and the cutting progress.

The next one was easier, but still took a lot of time.  Would you believe
like 6-8 hours?  It was a player though.

I like working on the larger MPs better.  Its easier for me to get inside
the chamber and the facing work is more spread out.

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