I'm not familiar with that particular skimmer. does the body come off that [broken] base? what's the purpose of those thumb screws? If it comes off, I would suggest getting a new bottom plate, if the base and bottom plate are a sealed unit and it still holds water, weldon 3 or 4 will do the trick. But if there's an O-ring that seals things up, using weldon to connect the broken pieces together may not be strong enough to hold things together.
If it's going to be in a sump/refugium, then sealing it may not be a big issue.