Must be a built in safety screen. Dont remember ANY
rectangle color CRT without it. I wouldnt mess with the tension band
unless someone has done it. IIRC Admirals had big rubber
corners you had to cut for some swaps like the 23EG's BUT its
been over 40 yrs !!!! Zeniths had the ears as mounting &
the big fold-up DGS shield but I dont remember any big
rubber corners. Truth is its been to damn long & my memory
sucks..... May be you are hoping for a sub where there is none ?
73 Zeno