Once I'd decided to repair the tear, I chose to also replace the holey lining on both ends. I cut out two pieces, as neatly as possible. Fully replacing the lining is probably beyond my skill-set and enthusiasm at this stage but I think I'll do OK with these smaller sections. Fingers crossed!
Once the worn fabric was removed, I could see how dry the leather was - in spite of conditioning the outer side. I gave each end a liberal dose of conditioner. I'll leave that a few days before trying to patch the tear.
After pondering, I decided to remove the pocket elastic. The trickiest part was working in a deep bag, in a poorly lit room! Yes, I could've found a head-torch rather than balancing this little one but where's the fun in that?!
I threaded a double length of new elastic through. It's pinned firmly, ready for the next step. We have a property inspection later this week. I find them stressful, so am probably doing a lot more preparation than is necessary. On the bright side, while I'm busy with those other missions I'm also thinking about the best way to patch the leather tear - and attach the replacement lining sections. I just hope the reality will be a good match for my vision!