hi
i have used 33" and 35" studded offroad tires many years, we have local shop here that sells big tires, drills and studs those quite cheap. also many of my friends are using studded tires under their "offroad rigs" but otherwise its not so commonly seen in finland, many ppl. have only one round of tires that they use all the time.
i have now noticed that better is to use a bit smaller studs than you could fit to the tire, just add quantity of those instead. rubbing bigger studs against some rocks will damage tire around studs more (like in those tires in above pic. for sale btw.) than small ones.
i think most of the tire shops can arrange studded tires or making those for you...
and for a tow ball... 78 its so old that nobody can tell how old i your tow ball and when and where its done, just if its made properly and its strong enought it will be just fine.