I just noticed that attach failed and only the pictures got uploaded. Here comes schematic, PCB layout, program, and assembly instructions.
I figured out a trick for extending the frequency range on small PIC microcontrollers whose Numerically Controlled Oscillator has an undersize (16 bits) Increment register. It's in the program comments but I didn't test it as I'd already cut off the programming header. Affected parts are PIC10F320/2, 12F1501, 16F1503/7/8/9, 16F1713/6/7/8/9.