
Cork is about 1/8" thick, as hard as it is to find cork gasket material, this might be an option. IKEA - West Sacramento today.
For some locations, I have used cereal boxes for gaskets with good success in the past.
cts
Joann, the craft store, used to have a good range of materials that were useful in the workshop too. Pity they went under. Michaels which is also a craft store, doesn't have nearly the range - mostly kitschy junk reeking of fragrance
Craft stores surprized me; some had the proper materials for replicating seats etc. not just for crafts.
I think some folks used emptied 12 packs from their beer purchases to make gaskets as well. Nowadays, probably less expensive that buying a box of cereal!
Oh for the good old days, walking into your favorite parts house and asking for them to cut 3 foot of the medium off the roll in back.
The last I bought at the NAPA was almost as hard and dry as what I already had.
My wife gifted me some paper from the rolls of wrapping paper that is not a card board tube. Looks like it would about like cereal box/beer carton. Current plans are fire starter in the wood stove.
I went into the local parts store here, asked about purchasing some gasket paper, they produced a package of paper about 12" square, multiple thickness, all for a piece of paper about 4" x 6", Cereal box working just fine! Try to find a place that has rolls of gasket paper today, like finding frog's teeth. - cts
Another I have used in the past is the box parts are in, yes a few cat part boxes have been place in various locations including thermostat housings and the touch of grease on one side as per TK88 suggestion in the past to make it easier to remove if required after assembly