HD Mounts

I used to ride a 60's rig 35+ years ago and had a hoot.

I saved a bunch of parts and am restoring a '65 Electraglide with period hack.

I looked at a newer bike today and noticed the front lower mount is attatched only on one side of the frame.

This eliminates the two point mounting and the crushing of the front pipe.

My question would that mount fit the older hack-they look the same.
And/or is oneside only harder on the frame?
The old steel rigs are really heavy.
I am using original trail forks.
Going to be my ride into the sunset.