Looking into plank strippers , they all had problems because they want to follow the grain. Found this on a model railway site and modified it to have a longer support ( part C on my sketch). The sheet can't move so it cuts perfect. It is fixed in both width and height but for a 10 min job you can make what you want. Only tried it on Basswood and it works a treat
Excuse the woodwork, I made it quickly from scrap to see if it would work
