JP1 Remotes

1. Device: Sherwood RD 7405HDR
2. Type of device: Receiver
3. Year: 2010?
4. JP1/UEI Remote model: URC-9910B01
5. Do you have a JP1 cable? No
6. Still have original remote? Yes
7. Checked the file section? Yes
8. Checked Pronto file section (at R/C)? Yes
9. Partially working setup code? No
10. Learning remote question?

I used up all my learning memory just teaching each device the same vol+-/mute. It would help if Volume Lock worked on learned volume or keymover could duplicate learned keys, but it seems that it doesn't.

11. Have you tried the JP1 Lookup Tool?

Yes, I tried all the setup codes it shows for sherwood/audio and none are found in the URC-9910

Sherwood receivers use NEC1 device 131.69, and as you've already seen, the URC-9910 doesn't have a setup code with that fixed data.
I'd say you need to break down and generate a WAV file, or better yet, get a JP1 cable, which would allow you to readback and modify the programming already in your 9910.