TRC975 cassette tape head replacement

I have had a TRC975 for quite some time now and besides cosmetics, everything works aside from the corroded tape heads on both decks due to storage in less than ideal humidity by the prior owner which also caused the aforementioned cosmetic tarnishing of most of the chroming.

I was told by a local electronics repair shop that specializes in classic audio that the tape heads in this box were toast and were proprietary making replacement the only option if I were to find the obscure part.

Is this true? Would any of you guys be able to shed some light on where to find a replacement or substitute if one exists?

How bad are they? Post pics. I have actually cleaned up rusted heads with rubbing alcohol and pencil erasure and they came out pretty good. You just got to remember to demagnetize head when your donee and it takes some rubbing

Oops forgot the pics!

Here they are:

Click on images for more detailed higher resolution pic to pop up.

I would pull decks out and clean everything real good before replacing heads

Is there any guides or manuals out on the web for doing that?

I've had quite bad luck locating those when compared to finding information for my gf909 ala JDM gf777.