To save you the effort, I'd do you a straight swap on my R1100GS - It's newer than the one you have, and therefore clearly better. No need to thank me.
geez, both barrels glued on with copious amounts of silicone lots of which looks like it's decided to go walkabout. No guessing where that lot ended up.
Rear oil seal had been replaced and failed. Closer look and you can see it was driven in with a punch, punch also slipped and marked the casing . No damage to the sealing surface. It'll be dressed on rebuild. Pump seal was failing.
Id love to see the workshop of whoever put all that red sealant in, must be like some horror show. How do you ensure none of that crap is blocking an oilway somewhere?