Rifle Brigade Officers different fittings

[Mike H]

Ive been having a look at some Rifle Brigade Officers badges. The last but one pattern ,worn up until 1952.
I found two examples of a HMed silver Cap badge with different fittings. One has east and west lugs as youd expect to find. The other has a central screw post and a small pin in the 12'o' clock postion,it doesnt show any.signs of ever having lugs fitted.
Does anybody know why this was done,any significance in it ?