A quick learner from Illinois says:
December 28, 2013
I'm trying to ID this latch. Same measurement as Swisco part # 40-185. Its stamped Wartian Lock Co DSL 1100-6 Thanks
Paul from SWISCO responded:
December 30, 2013
I agree, the 40-185 looks close. I think it's a good place to start, but just make sure all the dimensions we show are identical to your own.