The Photomic T Prism is the second model Nikon produced, and the
first that allowed TTL metering. The first Photomics have a lens in the
top left corner, as seen from the front.
I bought this for $100 on the San José fleamarket in 1989. It looked a
mess, frankly, and still is, but it more or less told me to buy it.
The stallholder claimed that it had been to Vietnam, but his general
manner made me think that this was so much codswallop. It's possible,
though: the camera has certainly seen less than loving care.