Yes, definatly a Huffy built bike, the chainring, forks and chainguard are dead give aways. As for the numbers "W 11XXX...", the "W" signifies it was to be Western Flyer, as an "S" would be Sears/J.C.Higgins, an "H" for Huffy and an "HW" for Hiawathas. I have a 61' Huffy built J.C.Higgins Deluxe with the same chainguard but with the earlier chainring. Id say it was a 61' (but the chainring makes me think 71') and sold as either a Western Flyer or (less likely) a Sears/J.C. Higgins with a "W" designated frame like yours and like my 61' JCH also starts with a "W". The 505 or 506 I think was a cataloge number or something.