Ugh, HTMLView... that brings back some bad memories. I had a hell of a time tracking down a working set of archives a number of years ago.
Seems I've got v12.6 of the .mcc (Jan 3, 2000), but I can't remember where I got it. It might have been from
this old thread (thanks blobrana!), but now that link is unfortunately out of commission as well. I can't find that archive on my hard drive, but I'd be happy to send you the .mcc itself.
It doesn't generate beta timeout messages (from what I can tell), but if AmRSS demands v13.x, there's probably not much you can do until the v13.x 68K build is fixed.
One last thing to try: use the v12.x .mcc with a v12.x .mcp. Don't know if that'll help, but it might be worth a shot.