Hi Jack,
I'll live with the 2.5 Hp outcome but still remain defiant that the air cowl has been changed as the date is just incorrect.
I'll have to wave the white flag on this topic as it was I that originally supplied the photos for one of these two examples to you Jack. The set that shows the mower in the doorway with the red bricks in the background, as that lot gave us some valuable info about the last of the 14 inch variant before SB scrapped it along with the 20 inch example and substituted them for the Morrison designed machines as you've pointed out in the above post..
Cheers,
BB.