radiator leaks - confirmation, replacement, etc.

[jbrush]

hi folks,

well, i'm moving forward on getting the rough running problem worked out, and now want to address an ongoing issue: coolant loss. since i got the vehicle it's been intermittently losing up to a gallon of coolant a day. i've been on top of refilling (with water), and don't think it's overheated.

my assumption is it's the radiator alone, based on the encrusted blue scuzz near the inlet and outlet -- see photos. does that picture look like a busted radiator to folks? i've looked in an initial way at the hoses etc., and there's no other obvious leaks.

my approach is to find a used radiator from a salvage yard and swap out. this is cheaper than recoring. i'll do a garden-hose pressure test, and hope for the best? any thoughts on this?

finally, this's a very simple question, but what's the radiator-like thing forward of the radiator itself? you can see it in the first photo "above" (behind) the radiator top. is this the heater core? just a bit confused by what at first blush looks like a "second radiator".

thanks!
.b