Yes, many by mail courses during that period. From Indian club training (actually pretty intense) to dynamic tension (muscle against muscle resistance/holds). Kettle bell courses. Also many hand balancing courses offered.
George Jowett, pretty famous at the time, also sold exercise equipment, based on leverage with the weight only on one end of a bar. Adjust muscle resistance by sliding the weight higher or lower on the bar. Most , like today, usually sold exercise equipment with their courses.
Exercise springs (or cables) were also offered. Could adjust the resistance by removing or adding single springs to the handles. Could pull or push these exercise springs. Europe use to have spring pulling contest back in the day.
Lot of military style old time exercises courses. from Prussia, German and British training manuals mostly. usually bwt.
Even Hindu training, based on their old time wrestlers training (said to be over a thousand years old...probably started by Weider, no doubt). Hundreds of reps (300 to 500 reps) of bwt squats (rock bottom to up on the toes at the finish), Hindu pushups (dive bombers really) and neck/back bridges. These three exercises were called Hindu royal Court, which I have used with very good results at times. Got involved with them in high school, can be quite brutal at first. I still do 50 to 100 bwt squats before leg work .
Good Luck.