Tom:

I checked the numbers and that is what they are so possibly that number on the engine with 2520 is not a goof up??? Maybe once we figure out what these numbers are for it will make sense??

Any other Wallis or Massey Harris 12-20 owners out there want send Tom there Serial numbers with engine numbers and extra engine number so we can add it to the list to try to figure this mess out?? Your help would be greatly appreciated.

I would especially like to find the Wallis / Massey Harris 12-20 with Serial number 106012 as I own SN 106011 and SN 106013 one is a Wallis and the other is a Massey Harris just curious to see what the extra engine number would be, it should be between 6676 and 6680.