Those vintage Tamiya kits are worth big money. I saw an original 959 R/C kit, still in it's shrink wrap sell for almost US$2k on eBay recently and a hobby store owner I know was furiously bidding on it. He was pissed that it went higher than he could justify.
It should look awesome when it's finished. Look after it, and for heaven's sake - don't smash it all up!