The thrust reverser unit as fitted to the RR Spey on the Bac1-11 has a casting just like that. The reverser twin rams attach to it. One casting on each side of the reverser unit.
The large hole at the bottom is the pivot point and the twin rams attach to the ‘U’ sections at the extremities at the top of the photo. The 2 holes seen just inboard on top are used for fitting a ‘gag’ to prevent operation of the reverser unit.

I stand to be corrected though.

CS