Congrats! That pickup looks better than the split Mustang pickup.
Could you please provide measurements of the Serek LZN B90?
I have the opportunity to buy a used Squier Mustang and I am considering doing something similar, using an EMG 35HZ pickup, but I will have to purchase on line so I am wondering about how much the pickguard and the body will have to be cut.
Dimensions are on the Serek site:
Adjustable B90 Single Bass Pickups - Serek Basses