I fashioned a cone wrench using a rotatory-tool with a cut-off wheel. Basically making one cut horizontally for the thickness and a cut vertically to complete the cut.
I used 4 cut-off wheels doing it, going slowly and dipping the wrench in water to keep it cool. Total time to make this wrench was about half an hour.
I am very skilled with a rotatory-tool, so those with less experience using a rotatory-tool may use more cut-off wheels and take a bit longer to do the job.
It may help if the wrench is but in a vice when making the cuts. I didn't do this but I don't recommend this be done and always wear safety glasses when using a rotatory-tool.
It's a long story why I did this but it is done and now I have a nice strong 14mm cone wrench.