I think that means Kg1 is a LP only, if memory serves.
What I can't answer for original68 is:
1) if the carb he has IS the kgn1 for the WD45. For some reason I don't recall the books I've seen showing the spacer between the LP lower ave portion, and the body that mounts to the manifold.
2) what size top opining the ensign Kng1 for the 45 had. I'd guess Original68's is 1" form the 1" Kngl he gave us, but I don't know about correct for the 45. AND I thought I read here at yt that ensign had more than one size in all Kngl's.