That should be 17/12/04 for the date of manufacture. The number breakdown is Model 12F802 Type 1975-B1 Code 0412175.
An Illustrated Parts List pdf download is at:
http://bsintek.basco.com/MDEXResultsPages/PDFDisplayPage.aspx?fileName=18hruJXHnfBhU7yThe Briggs and Stratton Service Manual for this model is P/No 270962.
It is available in the 'Engine Manuals and Parts List' section on this site [paid subscription required], or there are a few free views/downloads of it around. A Google search can find them.