1967 Mustang / Cougar Strut Rod Connection

My son recently bought a 67 Cougar S code as a donor car for the restoration of his 67 coupe. The Cougar is nothing more than a salvage vehicle but we anticipated using the 9" rear, drive shaft & front end with disc brakes along with other misc. parts. With the exception of the sway bar, we are not re-using the suspension parts from the Cougar.

I noticed that the strut rods on the Cougar did not bolt to the top of the lower control arm as does our Mustang. There is a shackle that is bolted to the lower control arm and the strut rod connects to the shackle with a single pin bolt. I have not found this in any of the parts magazines and it does not appear to be a modification but I could be wrong. Is anyone familiar with this set-up and or why it was used?

Just curious.