Anyone had any luck finding a sheet on the correct foam material to make a new seal/gasket for their Monster tube? I will buy one if I need to. But, if I can find the material, I can keep plenty of "spares" on hand.
Try your local DIY or hardware store. They should have foam "tape" for draught excluding or gap sealing in various widths and thicknesses. A little experimentation should give you one which will suit