Door knob help (backset)

Hi all. I am new to this site and was wondering if someone could please help me.

I live in a condo complex that was converted in '73 from apartments. I am currently trying to replace the existing door knob and came to find out that the back set is longer than the standard 2 3/8". It is 3 3/4", yes 3 3/4".

Does anyone know where I can purchase a back set of this size????? I can't seem to find the make of the door knob/handle. I bought defiant dead bolt and door knob set to put in. The dead bolt is installed and working, but I can't seem to complete the regular door handle because of the odd back set size. I've already torn the existing door handle apart and can't put it back together.

PLEASE HELP

Thank you in advance.

 

Try "FSB USA" Good luck. They still make the jig for 3-3/4 backsets. Plug hole and re-drill?

INDII