I recently acquired a faulty 6245 which was apparently unrepairable. However it turned out to be a hand-fisted techie splashing solder in the unit.
My unit does not have any of the internal options, specifically the GPIB option. I have the service manual and I am in the throws of re-making the board. The manual does have the component placement and that will help. However I know service manuals are not always up to date and do contain errors. Therefore if any one cares to post a few high-res photos of the option boards, specifically the GPIB option. I will bless you at Christmas.
Many thanks and keep safe.