Mine came with a filler and it's very easy to make one if you don't
have one.  The measurements would probably be specific to yours since
all of these boats were built semi-custom.

Mine is 3/8" plywood with a 5/8" X 3" fiddle across the front to match
the fiddle around the berth.  3/4" X 3/4" cleats are screwed into the
plywood and the fiddle as well as to the sides of the VEE to support
the filler.

We also mounted a cleat on the bulkhead above the door to the chain
locker where we hook in the fiddle of the filler.  Then we mounted
padeyes in the opposite end of the filler and on the headliner.  When
the filler isn't in use it hangs up there out of the way.

Harry Schell
1981 V42CC