The neck angle on my ES-1/330 build was also a bit too shallow to get a decent low action. I ended up replacing the bridge post bushings with ones that sat level with the top and also cut the saddle notches a bit lower in order to get it low enough for me to be happy. https://www.buildyourownguitar.com.a...l=1#post204201

You'll have to do a search for suitable replacement bushings, as a lot have the lip on top which adds an extra 1.3mm or so of height. I think these were from the TonePros locking stud set I got for my GSJ-1 build and didn't use as the existing bushings were fine. You'll need an M8 internal thread.

You can also use a triangular or square needle file to deepen the saddle slots, but it's neater if you can use nut files. Just don't go mad as it's easy to cut too deep. You may find that deeper saddle slots will

Nice looking guitar, so it's worth a bit of effort trying to get it set up properly.