Bainzy, you can get various buffing add-ons for hand drills at Machine Mart IIRC. This will allow you to thin out the poly finish and achieve a slightly better sustain (well in theory). You screw the buffer (lambswool or various foams) onto a spindle that gets secured in the same way as a drill bit.
It's a nitrocellulose finish - but I expect that buffer should work just as well - thanks for the tip, I'll look into it this weekend. I would've polished it before putting it together, but I didn't have time to wait for the nitro to fully cure - I had a gig to play the week after refinishing it that I got into all of a sudden. It's been about a month now though, so next time I restring the guitar I'll sand it out and buff it.
What nobody seems to realise is all the hype about Marshalls comes from the original amps of the late 60's, not the JCM800's, and especially not from the modern amps. When you slam a chord on a real vintage Marshall or reissue modded with original parts, you'll grin from ear to ear and think "that's the perfect guitar tone I've been hearing in my head all this time!". It's just a shame that Marshall lost their way a bit after the mid 1970's in how to build amps - they forgot that components are what makes an amp just as much as the circuit path they use.
Besides, we want aggressive midrange don't we? I thought we were playing c--k-rock here, not *lose all mids so you can't hear my cr@p playing in the mix* emo-metal!