This may be the same thing as what you describe as "traditional off-the
rack Martin-style enclosed" tuners, but I used these:
http://www.stewmac.com/shop/Tuners/Guitar,_solid_peghead/
Gotoh_Vintage_Scalloped-knob_Machines.html
On my OM (which you've seen - don't know if you noticed the tuners at
all). I really like the look.
I agree with Todd that open-back tuners look pretty cool on a traditional
guitar. Waverlys are awesome, but waaaaay too expensive for me. I just
noticed that Grover is making some nice looking open-back tuners now
for a very very reasonable price:
http://www.stewmac.com/shop/Tuners/Guitar,_solid_peghead/
Grover_18:1_Sta-Tite_Guitar_Machines.html
I think I'd go one of those two routes. Give me a call if you want to get
together again to take a closer look at the closed-back scalloped tuners
on my OM. I'd offer to let you take them off and put them on yours to see
how they look, but I drilled the pilot holes on a couple a little too small,
and they ain't EVER coming off!