....."110 Kodachrome slides my Dad shot".....
I did not realize there were 110 slides.
I am not exactly a life-long photographer, so there are A LOT of things "I Did Not Realize".......but 110 slides surprise me for some reason.
Not only 110 slides, but beautiful little 110 "Pocket" Carousel projectors.
Kodak also offered a service where they would dupe 35mm slides on to the 110 slide duping material. People like travelling salespeople could reduce the size of what they needed for their presentations.
I have two of the projectors and a few pocket 110 trays. I don't know whether the projectors will still function - they are on the incredibly long list of things to go through to wrestle the photographic records I have inherited (prints/negatives, slides+++++, regular 8, super 8 and a couple (I think) 16mm movies).
By the way, you could also get your 110 slides mounted into regular 2"x2" mounts, or you could get "adapter" mounts that the 110 mounts slid into for the purpose of projecting them in a 35mm slide projector. The resulting projected images were pretty tiny though unless you had something special in the way of a projection lens.
Getting (sort of) back to the subject at hand, I expect one of the reasons that I sold a lot of 35mm film and cameras in the late 1970s - in a department store camera department (among others) at that - was the availability of fast, high quality Kodachrome processing and Kodachrome film sold with Kodak processing included.
If you dropped your Kodachrome at our store on a weekday morning, the developed and mounted slide film (or developed movie film) would be back in our store for customer pickup the next afternoon - at no extra charge to the customer. Any Kodak dealer was entitled to participate in the pick-up and delivery program. There were a lot of them throughout Western Canada.
Or you could mail the film in, it would be developed on the day it was received and mailed back the day after. During busy times, the North Vancouver Kodak lab ran processing runs 24 hours per day. A huge percentage of the non-movie film was 35mm.
With that volume, I got to see the results from a lot of customers' 35mm work.