45” Harley Frame - Mating a Servi-car and WL

I have a servi-car front loop that I had planned to build a tail section for but just picked up this 2/3 of what I think is a WL frame.
A few questions

• I presume that the boss for the support tube under the backbone was cut off. HD did not make frames without them correct?
• Any reason not to use the entire servi front loop and only the rear legs on the WL? Anything different/superior about the WL trans or motor mount/castings?

Obviously I’m not too concerned about it looking perfectly OEM.

Thanks