[HECnet] DECnet for DOS / Rainbow documentation?

I tracked down Dave Mitton who was the team lead on DECnet for DOS and later VAXmate version and Pathworks after that. Dave made the following comment: "The Rainbow BIOS was very different than an IBM PC type BIOS, so there was additional code to keep that straight. Also the Rainbow's serial adapter was different (and better!) than the PCs." - so we are looking for DEC Rainbow specific versions of DECnet. My request is as before if anyone has a copy of DECnet for Rainbow 1.1 I would be glad to get a copy. thanks.