So, the front fork was changed to 26, to accommodate a 26 wheel, (or maybe whatever they had)?
The thing with Dyno Glide headsets, is that the cups are for larger 1-1/8" threadless forks, i.e., 34mm headtube ID; however, the threaded forks are 1" OD. Dyno used a custom headset for these bikes. If the original parts were not saved, (or went with the wrong parts upon separation), then the adapter method is a best way to go. The 2mm adapter shim reduces the oversize 34mm headtube to fit a 1"/30mm road bike headset. [Additional stacking height washers, or other means, are required if the steer tube of the fork is too long for the short headtube].
I took a second look at the 24" bikes in the Dyno Kustom Kruisers Katalogs, and it appears that the artists took liberty and merely shrank the 26" bike pictures, and labelled them as 24" bikes.