Creating a new MTX900 codeplug

[N4RPD]

I'm looking for the "how to" on creating a new, from scratch, codeplug for the MTX900. I have the RSS and I'm able to read, write, and clone codeplugs between 2 radios.

I have a couple of radios that have the codeplug completely erased, no model or serial number reads from the radio when read by the RSS. I think this means that I have to create a new archive file from scratch to create a new codeplug? I think those radios are model# MTX900S, can the MTX900 RSS program 900S's also?

Am I on the right track or lost?

Thanks,
Rob N4RPD