Steve -- looking GOOD, that's a super-clean, precise paintjob, it's almost a pity to slather dirt all over it! It's going to be a real beauty! This is Italeri's? It's looking excellent, though I know how much work it takes at the building stage to line up those parts correctly.
On the tracks, I don't think I've ever done the pin-melt trick. I've never tried finishing Italeri tracks yet, though, and I've heard they can be stubborn. It usually takes just some superglue to join Tamiya tracks, and I once stitched together some cut and shortened tracks with black thread, reinforcing cya on the ends.
Good luck, but it looks like you're on a downhill run to the finish now -- I look forward to seeing this animal dirtied up and bearing tracks and tools!
Cheers,
Mike