Well, the crappy old PVR finally died: Stone dead; wouldn't even switch on.
So, I now have a
Panasonic DMR-PWT560GN, which set me back about $450.
Seems to do all that I want, although getting it to run via my VPN will be my next challenge.
...and, before you say it, Sharkboi

; it is NOT MPEG4 compliant.
However, I have not yet found non compliance with MPEG 4 to be an issue.
If I encounter a .mpeg4 file, I can convert it, but so far I haven't needed to do so.
Anyway, early days, so I'll see how this goes.