Hmm, didn't know Gokigen-Seimetsu had a YF-19 conversion kit, I have both conversions he made for the YF-21; one for Guardian and one for Battroid. He also made a set of VF-19F/S conversion wings and another set of underwing stores for the 19.
This is also the same guy who made all the metal parts for the VE & VT plus all the head laser barrels for pretty much every battroid version Hasegawa ever made.
Another guy made a straight kit of a 1/72 YF-19 battroid, the name on the package for that one is
Kantogakuindaigaku-Mokeidourakukai (say that ten times fast).