Question about “buddy buckets”

[72blu]

Hi everyone, After many years of looking I have finally come across what I belive to be a set of buddy buckets for my 72 C10... after looking at the frame of the seats and comparing it to some pics ive found here on the fourms ive noticed mine seem to be a bit different.

I was told they came out of a 67 c10 but the frame is missing the flat section that bolts to the floor and also its missing the centre support that was joined to the middle frame bar.. there is no evidence that a support was ever there or that the mounting surface was cut off. I am just wondering if I happen to be missing some of the hardware required to mount these suckers in my truck.

Ive included some pictures so you understand what exactly im talking about.