Looking at the UPC number "01947 9" as shown in above post, I wonder if a possible break down is.
0 - Individual item not a set?
19 - American Flyer Rolling Stock Product Category? Maybe year released?
47 - Forty seventh item released since changeover or this year?
9 - Calculated check digit.
I realize this doesn't help with creating a data base of item number to barcode number, just some creative thinking.