Part rolls grey Flashband ,self adhesive (St Just TR19)

As above, width 15cm, bit battered and dusty but inside lengths should be fine . These are flashing strips ,may have been Bostik make (see online ), these have a peel off strip, are flexible, they are a lead replacement , should give a waterproof seal once applied (it is described.)..used with extra sealant glue to make sure, I think.