When you say "later" forks, do you mean the 1968ish 6 3/4" yokes, or the OIF things?
If it's the former, they can be made to fit by using the correct longer wheel spindle, it it's the latter, I feel your pain. Good forks but too ugly for this beautiful bike.
As the man says above, Ebay has most bits....just not always when you want 'em!