Shockabilly sizing?

All you Shockabilly owners,
How are these frames sized? I know the older ones came in S , M and L right? How would a Large somerville made Billy fit? Do they run a bit smaller than say, a YO Eddy? If I ride a M to a M/L YO, what size Billy would work? I am 5'11" with about a 32" real inseam.
Cheers,

Fatty
 
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