was leaving this to see where its going....
IMHO...
A good idea in principal....
A few thoughts.....
The list is getting a bit big an unmanageable, maybe split into Headings like common service parts, Cam cover gasket parts etc.
Also the accuracy worries me, consider saying what engine the parts are for, as for example there are :
7 types of cambelt kit
2 types of pollen filter
5 types of oil filter
3 types of sparkplug
5 types of battery
etc etc etc, the list goes on.
Not trying to dampen what you are trying to do, but fear it could be a bit of a white elephant...
If the information is not complete, then people may well end up incorrectly ordering the wrong parts, which can be an expensive mistake on special order bits.
A lot of people on here have access to the proper Vauxhall documentation in the form of the trade club site, or epc itself, maybe best left to requests and answers :-/
That said, if you pm me your email, I can send you something which may help.
We did at one point have a full tradeclub list of parts / prices but it was not easy to maintain accuracy so it was removed.