"It's sounds awesome."
"The thing is, I don't have the right headshell for the SL15 yet so it can only line up like 5MM short on the Feickert."
I use the Feickert jig. Baerwald pushes the cart the most forward of the 3 alignments. At least you can do other 2 with good results (of course with the inherent limitations) My hearing isn't sensitive enough to hear any real differences between the 3.
So you need a longer headshell with more slot to get the cart to align with the grids?