[cctalk] RSX11M tape copy

Hello all, I have transferred some simh .tap files to my PDP-11/23+ running RSX11M+. There I have tried to use VCP to attach them to a virtual device but I keep getting an invalid record format error. I then realized the simh .tap files most likely aren't organized correctly. If I attach them to TS0 in simh I can work with them. So now I am trying duplicate a tape into a new .tap file created using VCP. I can't for the life of me get it to work though. BRU doesn't support tape-to-tape and FLX doesn't complain but also never completes. Is there a process for tape duplication under RSX? The images were first transferred to my PiDP-11 using ftp in binary mode over TCP/IP. From there I used NFT in image mode and I tried both record and block modes. I have also seen the simh tape tools but there doesn't seem to be a tool to convert a simh file back to what would be on a real tape. Anyone have any information or pointers to get this to work? Thanks! -Peter