Firstly, these arrived in a Kluson branded packet. I don't know what the relationship between Göldo and Kluson is, but either way they make a great product.
The machining on these threads is second to none - I'm 99% positive that these are not cast, but are properly machined on a lathe. The threads match up perfectly with no inconsistencies at all, and the nickel plating is very even too.
As a modification, they work very well indeed. Drop them into your import ABR-1 bushings, and then simply seat the new bridge on top, it's practically invisible once it's they're in.
I'm looking forward to buying more Göldo/Kluson hardware if it's all as good as these! :)