There are four plugs for the main mast: Bottom, Partners, Hounds and Top.
Three of them, Bottom, Hounds and Top, are cut to size and fit quite nicely.
The plug at the partners needs to be sized, fitted and notched (to avoid creating stress points) and the Hounds plug needs notching, too, before I can glue the two halves of the mast together.
One thing about taking advantage of space in the barn - there is a LOT of space. My shop and where the mast is being assembled are as far apart in the barn as they could possibly be and the path between them is a bit circuitous. I ran out of steam yesterday while fitting those three plugs. Today is just too hot and humid for comfortable work in the barn. Tomorrow...