In a JD model a #6 is the biggest one and a #71 is a little smaller!,also a Model #45 ....... In a MM their is a 1210 is the big one and a 1200 is just a older model ,then they have a model E and a model D. I do know of several shellers are so it is up to you what you are wanting!
No sheller was available for the 323. To widen your search parameters, Haban made a compact PTO drive sheller that had decent capacity . . . . the JD 43 was popular around here as well. Big shellers in the area were either JD #6 and #71 or the M-M models previously listed. New Idea made stationary shellers, but I never saw one. I have a small Harvey 'Red Head' belt-drive, but it was also made with PTO. Sears marketed PTO shellers under the David Bradley name, too.