If the Type 13 class battleships had been built by Japan, what would have been the French, British, and US response shipwise?
Assuming through magic that the Japanese can afford this. Response would be in 1926, No. 13 assuming no delay between the launch of the Amagis and laying down of the Kiis followed by no delay between the launch of the Kiis and lay down of the #13 would be laid down in Dec 1924, realistically lay down would be in late 1925 or early 1926 given there would be delays.
France: No response, they aren't planning on fighting Japan on their own and their dockyards are limited enough they needed to build the Richelieus in 3 pieces and the Dunkerques in two, not to mention they are broke and need to fund a huge army
UK: Possibly no response. Any response would be in 1926, following a financial crisis in 1925 and with a general strike in that spring. Now 4 G3's could have been afforded without raising taxes based on projections I've seen on this site, if the RN also built 4 N3's, well we have higher taxes going into 1926 and trying to raise taxes again in that year might not be politically possible. If politically possible are limited by dockyards so probably a modified and improved G3, maybe keeping the 16", maybe going 3x2 or 2x3 18"
US: Without the WNT the US would have already been funding 2 new battleships a year in 1923 or so. Those would have been either an improvement on the SoDaks or a new design inspired by them 23 or 25 knots. So response would be a Design D esque battlecruiser, 12 16" guns, 30 knots, 12" belt, 5" deck on 54,500 tons with turreted secondaries, probably substantially improved given 7 years improved tech between 1919 and 1926
Of course this assumes that after seeing what the US was building in 1923 the Japanese keep going with a modified version of scheme K (which somehow gained an inch of belt armor and a half inch of deck armor while losing 1500 tons of displacement compared to the preliminary design) rather than basing it on one of the more powerful schemes like H, I, L or M with 14 or 16 16" guns or 10 or 12 18" guns