Mast Diameter is the same for all rigs:
2" at heel and 1-3/8" at head. If you use a mast tube
on your boat, cut the heel to fit its inside diameter as
appropriate. 1/8" more or less won't matter. A rectangular or
square 'box' to fit mast heel is also OK.
Note that the Bailey Rig spars are the same sizes as the
Batwing spars. Bailey 30 = Bat 36, Bailey 40 = Bat 47, Bailey
60 = Bat 70, Bailey 75 = Bat 87, Bailey 90 = Bat 103.
t f j: "to fit
jaws" or other mast fitting. See (not available
yet).
Otherwise, work from the spar's "mid" dimension.
Notes: battens in larger sizes seem to have
been oval rather than round, so the "Diameter" probably refers to
the longer vertical dimension.