Water pump indeed is the "Achilles Heel" of the 1600 T/C engines. Check the "weep-hole" for traces of leakage. It ~IS~ possible to change it without pulling the head, but better to do it "according to Hoyle." O/P after engine is up to normal operating temp should be 20~25 lb/psi, to 60 lb/psi at revs. Old joke used to be "If it ain't leakin' it's likely out of oil!" Actually they can be built without the leaks if attention to detail is applied on reassembly. Another thing to look out for is flex in the front frame. The Escorts and Cortinas would age (read: rust) and begin to exhibit a fair amount of weakness and flex in frame/chassis at the bulkhead. The Escorts got tubing braces, the Cortinas had to be fitted "aftermarket" with 'em.
BTW, I'm jealous: I've wanted an Escort T/C for years.