Um, Bruce, few emulsions are available in 2x3 sheets. For 2x3, 120 film offers many more emulsions.
Originally Posted by DBP
The Mini Speed was discontinued before Graflex offered the Graflok back, but Graflex did offer 2x3 Graflok backs for retrofitting on the Mini. These differed from 2x3 Graflok backs for, naturally, 2x3 Pacemakers, in having the FPS flash sync terminal in the upper left corner of the back, as on the Mini's original spring back. I've seen 'em. Also, normal ordinary 2x3 Pacemaker Grafloks can be fitted to the Mini. Nowadays this make little economic sense. But I've owned one such.
A Mini with a spring back can be used with roll film. Just put the roll film in a 2x3 size Adapt-A-Roll 620. I use 'em, they're offered from time to time on eBay.