CHUBB Custodial Lock - Can you ID type?

[Arcade Al]

Hi.

Asking if anyone can help identify this CHUBB custodial lock and number. It pre dates the 4L55 Chubb custodial lock, but would like to know its "ref number"
as well as any other information about its manufacture date etc. very little info out there about these except for some CHUBB pdf info sheets on the newer types.

Set up is nearly identical to the newer types appart from some facial surrounds and handle changes (anti ligature)

Thank you.

I have a T-handle "modern" 4L55 that is very similar to the one you pictured, except there is a surround on the lock indicator and the handle is powder coated. Not a lot of help, as I still don't know the number of yours. Finding info on the Custodial stuff is a challenge!