Thanks for the offer Brian, as soon as i get my list together i'll take you up on that cause, as you say, the lists i have are somewhat confusing and/or contradictory, although the 1997 Frank Meneret engine no. chart seems pretty straightforward thru Jan. 1969. i've used that chart to date my 2 45cc 3bolt engines, 276383 and 298102, to approx. Apr. and July, 1953. What do you think?