When you took that last photo, was the mast shoved all the way down? It looks like we may be seeing the part of it that's supposed to be below the forecastle deck.
On the other hand, photographs can be deceptive. Maybe what we're seeing is distortion due to the angle of the picture.
I have to confess I don't quite understand the connection between the kit-supplied "shroud and ratline assemblies" and ballast. Just about everybody else who's built one of those kits has complained that the kit parts are too long, and impossible to get taut. In any case, I don't think I've seen a finished one whose builder made the kit parts look decent.
A thought: is the ballast getting in the way of the mast, and stopping it from going all the way into the hole?
I've always thought Lindberg was onto something with the idea of the flexible plastic shrouds and ratlines. The other sailing ship from that period, the Wappen von Hamburg (aka "Captain Kidd") has the same feature. But the designers made two goofs in the concept. They didn't measure the masts carefully enough, and they didn't make the ratlines skinnier than the shrouds. So far as I know, those two kits are the only ones ever produced that handle the shrouds, ratlines, and deadeyes that way.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.