John I have searched for that, as others have no doubt tried, but come up with nothing.
I have found 91,524 items within that NSC & 176,137 Brackets none of them that share those two parameters that are British. Nor could I get any sense from items that included the manufacturer's number 33811.
Zooming in, as I neglected to do originally, it looks as if the NSN is actually 1095-99-2505-026 (rather than 1095-99-2503-021)
That gave a result as "Cancelled without replacement"