Felt hats are redundant to BLMs since electrum circlets. I don't think you'll be able to easily shift even double melded hats.

You could try Vit stacking felt robes of the mind for a WHM enhancing magic build but I think thats quite a niche market.

felt coifs +1 would be good ^^
Woolen yarn +1's I think are good. Also just selling felt +1s

Woolen tights stacked with int+mnd / int+pie