As always fellows, thanks for the encouraging comments!
Petey, I do make a long stick then slice it to bits of the needed length plus a tiny fraction. They are slightly "proud" of the tray top, but get sanded down flush after assembly.
At least with the long strip, they are all the same and I only need to feed against the fence to cut the panel slot, bandsaw the bit off, trim the stick end flat, then push up to the fence to cut another slot. Boring but efficient.