Yep, they do; I've got one. Sits on an accessory shoe (which can, in turn, be the sort with a tripod socket underneath, clamp onto a stand, etc.), has about a six-inch PC cord and presents a hot shoe on top. Cost about $15, IIRC, but might be less if you can find one on eBay. Folks usually think of them as adding a hot shoe to a shoeless camera rather than adding PC to a flash, but it's the same thing...
Well in this case, it appears that his SB26's have both pc sockets AND built-in optical slaves, so he really won't need anything additional. Except maybe for a couple sets of rechargeable batteries.
I'll advise you that, if you're doing any professional work, carry an EXTRA sync cord because they are notorious for crapping out on you (I assume the wires inside get damaged from being wound up or twisted or whatnot).
The radio transmitters sound pretty sweet though -- particularly being able to trigger them through walls and such. Not necessarily applicable for what you're wanting to do, but could be pretty sweet for light painting at night by placing flashes in various spots throughout the scene and triggering them remotely.
So, off the topic of strobes for a minute, I'm surprised you ended up getting the RB67 after you snagged that sweet-@ss deal on the Mamiya TLR, but the RB67 is definitely the ultimate studio camera, and a step up in terms of film acreage (
hectareage for those of you outside the USA).
And on another topic, I'm betting you intend to develop the Acros in the Rodinal, but it's like my favorite film in Diafine -- crunchy, in a good way.
