Frankenstein Meets Popeye?

Okay, I think regular readers will grant that I have a rather spooky if weirdly selective memory for detail. That said, I barely remember this roadshow kiddie matinee even though I did attend one Saturday afternoon circa 1972. Now, at the time, I hadn't seen Popeye cartoons in years as they weren't being shown locally. The last time I had seen one was when we were on vacation in North Carolina. Ultraman, however, was hot in the Midwest, having been rerun to death for several years. The prospect of seeing him team up with the one-eyed, spinach guzzling sailor to tackle the Werewolf and Frankenstein (his monster, anyway) was too good for my approximately thirteen year old self to pass up.
As I do recall, however, I spent about 90 minutes in a noisy, crowded theater with the lights on and a bunch of pre-teen boys shooting stuff all over the place through straws while bad prints of TV cartoons played out on the big screen. At one point, two guys in cheap monster costumes stalked out from behind the screen and proceeded to walk through the seats supposedly terrorizing the children but, in fact, being pelted viciously by whatever was going through those straws! I don't even recall an appearance by Popeye! Ultraman also appeared only as a TV episode (seems like it was segmented between cartoons). I do recall that I really liked the Underdog cartoon as, like Popeye, I hadn't seen them in years at that point. Overall, though, this was the end of innocence. My last kiddie matinee. By the next year I was attending R-rated movies. Of course, after the novelty of that phase wore off, I embraced cartoons again. What's the point of being an adult if you can't enjoy cartoons? You think these things are made for kids?