Thanks Aldo. Here is the IPL:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6nptCVJ1DajI.pdf

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msozHP-K_ny7tH217FzoPu.pdf

Obviously it was made on 28 July 1986, in Plant 11. However I can't tell you where Plant 11 was - it is one of the many that no longer exist.

Comparing the pictures with the illustrations in the Operator's Manual, it seems to be an I/C.