I may have mentioned this before but back in the day (approximately 1971/72), I purchased several stills from both movies directly from MGM.
I don't recall you mentioning it before, but regardless of whether or not I just missed it, that's very interesting. It's an idea I never had, so how clever of you.
I didn't actually start to buy memorabilia from the films until about '73/'74. I began by getting stuff from a place called Cinema Attic (which, believe it or not, was an actual reputable company that advertised in the back of '70s magazines like Modern Screen, TV Picture Life, TV Radio Show, and the like, among the ads for things like Eva Gabor Wigs and Miracle Breast Enlargement creams!!
). If I remember correctly, one could send for a free catalogue of what they offered and then place orders from the catalogue. They had all sorts of stuff from both films - though not being the biggest hoDS fan, I never ordered anything from it - but being a HUGE NoDS fan, I ordered all sorts of things from it. Unfortunately, they're long since out of business. But my NoDS (and some hoDS) collecting didn't end with them because in the '90s I discovered a place in NYC called Ohlinger's, and every time I visited NYC, I bought tons of more stuff.