Um, disagree about the last sentence: this one goes to 31", nut to bridge, so even Beatle-scale may be too short, at least as far as Pyramids are concerned*: medium scale proper should probably work better. I may be wrong though, it happens several times a day.The Kay Pro's tailpiece setup reminds me of a Hofner...that extra string length at tbe tailpiece will rule out short scale strings. I would bet that medium scale strings would do the trick in this case. Strings specifically made for a Hofner's scale length are what you'd be looking for.
Beatles me. Perhaps the line of thought was, people who play shorties want thump, let's give them it.Why did Rotosound change the 77's for the short/med versions from the longer scales?! I love the tone of the long scale 77.. :/
If/when you get the bass, consider Thomastik-Infeld flats, short (actually 35.5" full winding length) scale version. I've got the E from that set and like it a lot, very lively (even though I managed to sweat it into a thumpier tone in less time than anticipated).
*(There were reports of people whose violin bass copies had too short a tailpiece and that was enough for the Pyramids not to fit; I got no experience with La Bellas so if they're a smidge longer I wouldn't know.)