Need Schematic for OLD Telex ANR

The subject line bout says it all.
My old Telex model 70800-003 finally gave up the ghost. They still
make a good passive headset, but the electronics doesn't work.
The set is no longer supported, or even repaired, but Telex refuses to
give out the schematic.

It appears to be a very simple circuit with few parts, but I'd rather
not completely disassemble the things to trace every thing out. Plus I
see no markings on the transistors.

Any help would be appreciated.

Roger (K8RI)