Hi roebuck. That model number is valid, and is a 187 cc engine. If that second digit were wrong, the engine size would not be 187 cc. The engine was made on 2 March 1979.

This is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6lnsHVJ1DajI.pdf

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

The part numbers are given in that IPL. If you have any problems finding them, let me know. The IPL only shows a Gasket Set, not a Head Gasket - the Head Gasket Item No. has been blanked out. The rings are Item 26, standard bore is P/N 391654.

If you send a message to Bruce, and tell him you need those parts for a Briggs 110908, he'll find out if a head gasket is available separately. From my search I think it is P/N 27171 for a Briggs 110700 series. A whole multitude of US sellers on ebay have them.