I purchased it from my guitar mentor who bought it new from the custom shop. the information is scetchy at best, i can not get anything in writing so far. but i will tell you what i have heard.
there were app. 250 made and 150 or so where made for one man...now i haven't been able to guarentee this part..they where made for zakk wylde. now i've never seen zakk wylde play a 375 deluxe. but that is before my time.
mine came from the custom shop with a screaming deamon in it at the bridge. it also has a wider neck then usual, and came with jumbo frets which was odd for 1977. (so i'm told) And was made in Japan
the origonal owner payed somewhere around $2500 CND in 1977 for it
but like i've said before i haven't been able to prove anything in writing..expecially now that jackson/charvel has been bought out information like this is hard to come by for these old shred machines.
my 375 deluxe is a red with a shimmer? basicaly it changes red tinges in different lighting, so it has a very neat effect on stage.
so basically i'd give a estimate of about 3k-8k with out anything in writing just cause it is a old guitar and they hold there shape very well. (mine is in mint condition with no wood cracking, worping, or gouges. and it has been on tour 12 times and played every day since it has had a owner) just goes to show that these guitars are built to last.
well i hope that you have better luck than i have in the past.