Really? I wasn't aware... I've seen a few occasional Mercians hereabouts; they're very beautiful frames. Come to think of it, you can get a full range of options with Gunnar as well.
Although speaking of 'poor man's Rivs' and custom mods, I just received a note the other day from the builder that the modifications (modernizations, actually) on my vintage 650b Panasonic are finally completed. Now I've really got to decide what color(s) to have it painted!
BTW, those Palo Altos are real stunners.