It doesn't need to be a generic magical repair all kit. It would be possible and logical to make a single repair kit for each craft, thereby limiting the total number of repair items to 7 (assuming culinarian will never be called upon to repair someone's meal). Logically each kit would be either NPC purchased or crafted by that particular craft, and to appease gatherers, would require at least one item obtainable only from gathering. Also a graded system of repair kits could also be possible, though this would increase the total number of repair items.

An example of several kits and their recipes might be as follows:

Novice Weaver Repair Kit: rank 10 weaver
1 bolt of undyed hempen cloth
1 bolt of undyed cotton cloth
1 bolt of undyed canvas
1 discarded satchel (obtained through botany)

Intermediate Weaver Repair Kit: rank 30 weaver
1 bolt of undyed velveteen cloth
1 bolt of undyed linen cloth
1 bolt of undyed woolen cloth
1 discarded satchel

Novice Leatherworker's Repair Kit: rank 10 leatherworking
1 circle of sheep leather
1 circle of dodoskin leather
1 mole sinew cord
1 antelope sinew cord
1 rusty box (obtained through mining)

Novice Armorer's Repair Kit: rank 10 armorer
1 bronze square
1 box of bronze rivets
1 brass square
1 box of brass rivets
1 waterlogged crate (obtained through fishing)

This would seem to satisfy just about everything desired in a more streamlined repair system, low numbers of required items, relevant materials, and a boost to gathering utility, without having to resort to a seemingly forced repair-all material.

(I intentionally included all available weaver materials in the 'Novice' and 'Intermediate' repair kits because the cap WILL be raised at some point in the future and there WILL be new materials added, if we start calling everything master level now, then where will we go from there?)