Spartite here too... but it's not leakproof by itself (at least not for us) I use a tape boot that seems to do the job..
As for wedges, they should be put where ever required to properly center (athwartship - measure it; don't simply assume the mast partners are truly centered) and properly locate the mast fore/aft for rake/bend.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)