Bill:
I held off responding to your post in hopes someone with more current knowledge might answer your questions concerning the Mifflin County Model Railroad Club. In the absence of a response up to this point, I’ll share the little I know about this club’s O gauge layout.
About 8 or so years back, my family was visiting relatives in Lewistown and my youngest son and I were invited to attend a Thursday night operating session of the club. My recollection of that visit is that the O gauge layout used both Lionel TMCC/Legacy and MTH DCS. I believe the O gauge layout had wide radius curves on at least one of the loops but, I don’t recollect what radius our host said they were.
There used to be a club member who posted on here periodically (screen name Forest) but, I checked this morning and he doesn’t appear to have visited the OGR Forum since late April. In any event, you might try sending an email to the address shown in his Forum profile.
Alternatively, I don’t Facebook myself but, the club does appear to have an active Facebook account and you might try contacting them through that.
I will share that the HO and O gauge layouts were beautifully done and, having grown up in Lewistown during the 1950’s/1960’s, contained many excellently modeled landmarks I remembered from childhood. I’ll also note the club members I met that evening were all very friendly and welcoming to my son and I.
Curt