I've had a 42cm LHT and I have a 50cm Salsa Vaya. They both have a standover of 70cm.

I have a couple frames (built as my commuter bikes) of mid-1990s 13inch Novara Randonees. Back then they offered the smallest sizes with 26" wheels. They are decent steel frames, lighter weight than the burly LHT. I've kind of been hoarding these frames. They have a low standover, about 67cm. I keep a permanant watch on ebay for Novara stuff and I got one of these frames on ebay a couple years ago and I have not seen one since. There has got to be some more out there.