If you do decide to repair I've used Rawlplug R Kem II. I've found it a bit easier to work with than the Fischer products. It's a bit less runny and also, I think, less greasy when dry. Small standard tubes so fits in a normal sealant applicator.
Screwfix stock it but you could keep the wheels on the local economy and pick some up from Twiggs in Matlock.
I do have some Fischer ATM so if you only need a small amount let me know and you can pick it up.
Lots of good beta in the hold repair thread, clean surfaces well etc, also useful is M20's about putting tape over the grip surface of the hold.