EKHKHK56 wrote:They would have been 19" stock.
The 1953 Season Order Blank shows under "K Tire Options"
3.25x19 Firestone Sportsman Tires, Front and Rear (N/C)
3.50x18 Tires, Front and Rear (N/C)
3.25x19 Front and 4.00x18 Rear ($2.00)
3.50x18 Front and 4.00x18 Rear ($2.00)
So the 18's are correct. Good used 18" rims are much easier to find. The rears are the same 1953-1969. Fronts are the same 1953-1963. As mentioned before, Fronts 1964-1969 have different spoke holes for the full-width front brake drum. Front and Rear 1970's-up have that funky squared-off drop center. Of course, you'll have to find a good used set, and then have them rechromed, which will take a few months. Unless you luck (and $) into a pair that are ready to go.
Modern tires are more available in the 18", particularly for the rear. Same for finding a usable pair of vintage tires. Given the choice, I'd go with 18"s.
On the other hand, my 54 KH came with 19" so I decided to keep it that way. The front was kinda rusty inside, so I painted it black and drove the bike for a year. No explosions, so I sent the rims to the chrome platers.
I'm really surprised that your wheels have pinholes - in the photos, your wheels look decent. But of course we can't see the insides.