Hi Bergy,
I think I may have commented on this fact when you originally put up the photos of the 3 machines together. I've always felt that the Kirby visually was the better looking engine on the wide 20 inch machine over the Briggs units. I'd take a punt and say that the primer was not period correct on those HK-30's as they were used more so on the H-4 4A engines which were used primarily on the 14 inch model 45 when they dropped the Briggs 2Hp Silver 6000 Series engines and SB changed over to the twin rail Series II design.
Regardless your static display piece is "simply irresistible".
Cheers,
BB.
