I have several sheets of 20mm thick B15 panzerholz / pakka wood. This is a densified beech plywood. It has similar material properties to aluminum, but you can cut it with wood tools. I will be cutting it down for some projects soon and anticipate having some off-cuts to sell. If you have use for this kind of material, tell me the dimensions and I can likely offer you some, at a reasonable price, once I've started cutting.