First off, sweet looking combo! All Monark, all cool!
As for you headset 'issue', I've used a 1" pipe nipple from Home Depot. It's a little 'DIY' looking, but if you're gonna stick with the patina look, it might fit in.
I had the exact same issue when I put a girls Monark fork on my Fatbelly Bobber frame (Huffy)
So, assuming there's enough threads on the fork, install the fork, thread on the top bearing race until it snugs up and holds the fork in place.
Then slip the spacer on,(I used my Dremel to clean up the inside so it would slide on easier) slip on the top springer bracket, then thread on the top nut.
If you want a cleaner look, here's some headset spacers on eBay.
http://www.ebay.com/sch/i.html?_trk..._nkw=1+inch+headset+spacer&_sacat=0&_from=R40
There is an another alternative. You could find another 26" fork with a shorter steer tube or use the stock 24" fork and flip the top springer bracket upside down.
Good luck dude!
Cheers,
Dr. T