Packing confusion

My gasket set confuses me, and the shop manual doesn’t help me. I’m in the final stages of reassembling my twink (1965 S2), and I’m not quite sure of the proper rear crankshaft seal material. The gasket set contains both cork and “rope” packing that more or less fits the recesses in the sump and rear carrier. So do I use the rope or the cork? Frankly, neither material seems up to the demands, but I suppose I should use the “least unsuitable” material? :confused:

With the 4 bolt crank use the rope seal at the rear and the cork at the front, soak the rope seal in engine oil for a few hours first. From memory the manual tells you not to trim the seals but I have with a couple as they seemed too long.