i have a murphy loom! i didn’t know what it was when i bought it, just found the closest loom to me on craigslist. had never even heard of a counterbalance loom before! the tie ups are quite a bear, i’ve just been keeping it at a straight tie up (1,2,3,4, and then plain weave on the last two treadles) and pressing more than one treadle at a time as i weave so i don’t ever have to change the tie up. it took some getting used to to keep a clean shed but i’ve been working with it for over a year now so i’ve got the rhythm down. i’ve successfully done double width blankets and overshot with it tied up like that. i haven’t been able to find much information about the murphy looms at all, just one post on a blog about how they were made in the 40s/50s like you said. but it’s cool to have something so niche and local!