Here is the dropout tabs. I made them from 1/8" plate steel. These forks have mounting holes fore and aft of the dropout, so I was able to make it really robust, but a single fender mounting hole behind the dropout would probably be adequate.




From your picture, it does not appear that you have anything to mount a re-enforcing tab to. I would seriously consider upgrading to a beefier fork. It's not really that expensive, and this is a critical safety issue.