[Groff] Old *roff utilities - found a diffmk, any checkmm?

[kollar]

While indexing Chapter 15 last night, I ran into a reference to a utility 
called "diffmk" that compared two *roff documents and created a third document 
with change bars in the right places. Hm... Google didn't point me to the 
original code, but I did find a Perl script called diffmk.p that purported to 
do the same thing. I haven't tried it out -- yet! -- but here's a link if 
you're interested:

http://www.landfield.com/software/comp.sources.misc/archive-name/volume06/diffmk.p.gz


In a desperate attempt to stretch out my break, I started hunting for checkmm 
or a remake. I had no luck, but found something Meg McRoberts posted here last 
year:

   Do we have something like checkmm available for the
   ms macros on Linux? [...] If you don't have access
   to the old source for checkmm [...] I may be able to
   get ahold of it with the rights to use it... 

http://www.ffii.org/archive/mails/groff/2002/Jul/0104.html

Meg, did you ever follow up on that? I looked at what's available for Plan9 and 
neither checkmm nor diffmk were there (both are mentioned in UTP, so it would 
be nice to be able to point readers to them).

    Larry