I just found an old tool wrap stuffed with wrenches -- a variety of good makers among those I can see, but...   The wrap is stiff as a board.  I guess it's oil cloth.  Is there anything anybody knows that will make it supple, even a little bit?  I'd hate to break it apart to get at the wrenches.

Hmm, Oilcloth and canvas usually don't get stiff unless someone soaked it in some kind of waterproofing stuff. However that weird synthetic plastic stuff that looks vaguely like leather does get stiff and brittle after a while.

I would first try just letting it warm up in the sun a bit and see if it softens.

The second thing I would try is plain water, I know it sucks getting the tools wet, but if the roll is plain cloth, it may just be stiff because it got wet before and dried out and rotted a bit, water will release the cloth, assuming it absorbs any.

If not, Perhaps a little light oil (ideally , neatsfoot, but probably any light oil will work if it's really cloth, WD40 sometimes works and has the advantage of drying up later so it isn't an oily mess afterwards , if it's plastic, nothing will work that won't also damage it, the plasticizer is gone), but test it with a small spot first to make sure it isn't going to dissolve it or take the dye out.
It is hard when you aren't quite sure what the material is....

2c

Have you considered steaming it?

Mmmm...steamers..with white sauce and linguica
and a touch of parsley, a diced shallot, a bit of lemon, and some nice real butter.

I don't think a tool roll would taste very good in there tho...


*ducking*