Your engine has some collectors value, and it's value will increase as the years go on. The 1953 date would be correct for it. It was the very first aluminium block engine made by Briggs and Stratton. You can still download the owners manual for that engine from Briggs at this link.
http://www.briggsandstratton.com/om/pdfs/100/6BH-Domestic.pdf
Rick, December 2006
