Ok... So this:

Is a Hagstrom Ultralux series Ultra Swede. (Specs: here.)

I want to know if there's a chance in hell that I'll be able to put humbucker chrome pickup covers on it without either ruining the sound, or breaking the pickups. Does anyone know how big the pickups are and whether or not this will work? (Note that I can buy several sizes, I just need a measurement of some sort.)

It's got standard-sized humbuckers, so yes, it's possible.

You're not going to ruin the sound.

However, do you know how to put chrome pickup covers on? You need to remove the pickups, solder the cover to the back plate of the pickup, then wax-pot the pickups again to prevent microphonic squealing. It's a bit of a pain the ass.