Adhesive used between ECS vapor separator and white foam gasket?

[shawge]

I have a 70 Challenger with CA emissions (N95) and it has the ECS (or EEC) vapor separator in the trunk.  While I was cleaning rust off the separator, I noticed what appeared to be some sort of adhesive where the gasket would go.  It came off with lacquer thinner and elbow grease. 

Is there supposed to be adhesive between the gasket and vapor separator?  If so, what adhesive should be used?

Here's a pic of what I'm working with.  ECS vapor separator, new gasket and old gasket.