If you check Google, there may be a woodworker's store in your area. These stores sell to cabinetmakers and hobbyists. Since you don't want a big piece of solid wood (just a couple of square feet at most) they may have a scrap end to sell you. A lumber yard or even Home Depot can point you to the right place. You should be able to get a piece of solid mahogany or even rosewood. You'd google hardwoods or exotic wood and something will come up for you. In our area, there are many Amish chairmakers so if it were me, I'd stop by the workshop and see if they had a scrap end of mahogany they'd sell me. In your area, there also may be a custom furniture shop or boatmaker or cabinetmaker as well. But most states have a hardwood store to sell to people who like to do fine woodwork.