I am thinking that since this is my first time finding EFCs that I could have been doing it wrong.
I did use a "hammer" technique, of using random codes till I found one that worked. Then I got clued into the "U-OFA-URC: Making Your Own Extended Function Code Tables" page.

I am finding A LOT of "Device Setup Menu" codes. they pepper the landscape. In fact most of the buttons launched DVD SETUP after programming DVD/VCR for 0784. I am finding and Blocks of non functioning codes. I have performed a few EFC +256 tests to prove to my self that they are the same. I must have been doing something wrong when tested the lower numbers,.
But I was doing Increments of ten and they were performing the same function.

I made a spreadsheet to sort out my work. Can we upload attachments?