technics SP-25 armboard

I need to a adapt an Audioquest PT-5 tonearm to a Technics SP-25 turntable base. The round hole is pre-cut to 5 1/2" in diameter and 3/4" deep on the table base. I could buy the official, original armboard but it is designed especially for the EPA-500 tonearm assembly and would need to be adapted for the Audioquest arm. It might be cheaper to build one from scratch with all the correct measurements. Any suggestion will be appreciated.