The engine was made on 9 December 1986.

Here is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6nptCVJ1DajI.pdf

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

Most parts are available for older Briggs engines such as that one.