Here is a beginning of a rcs plugin that uses rcsmerge, rcs, ci, co and rlog.
I have used it probably over hundred times but needs some work.

<http://www.reedmedia.net/~reed/tmp-sfhkcjkfrfh/rcs.pm>

Also here is a quick script to browse the RCS history to use for "historyurl".

<http://www.reedmedia.net/~reed/tmp-sfhkcjkfrfh/rcshistory.txt>