If you're looking for a JP1 solution, you should post your question in the JP1 forums. I didn't see any files for dual deck RCA VCRs either here in the Pronto file section or in the JP1 file section, so without an original remote to learn from the best I can suggest is that you try searching through all 256 possible advanced codes to see if you can find the functions. You can skip over all the codes for known functions.