If fork seals are leaking and you MUST ride on ... here is how you do it:
Top up fork oil (use 5 wt. or 10 wt. fork oil or ... ATF fluid in a pinch)
Wrap a few layers of rags round the fork tube just below the leaking seal. Zip tie them in place or use string or thin rope. This will at least keep oil off your brakes and tire and will absorb most of the oil for a day. Redo rags next day, top up fork oil.
If brakes are already contaminated ... clean every thing with soap and water ... or even gasoline. (rinse well after) Clean especially pads and rotor ... and don't forget to clean front tire!!!
Vstrom fork seal is a common size (for 43mm fork tube I believe?). Should be a few bikes that use same size forks. Common KYB seal ... but any seal of same size should work. (Chinese ones will likely leak after some time)
But cleaning it usually will do the trick. Like Mike says ..."Go slow and careful". Do not cut the seal with sharp plastic edge or some such. I also like to spray WD40 or something similar in and round the seal to sort of help "flush out" crud that may be causing leak. Wipe all down after, wash everything up, see what happens.
I rode from Colorado to California with a leaking seal using above method. No
worries on highway ... off road not good once you lose too much fork oil.
If you have some bits or part of the original fender you may be able to do a bodger repair using Zip ties or attach scrap plastic sections on well enough to keep grit and water out your face. Lots of things will work as a fender if you can attach it firmly ... also ... you may be able to adapt a fender from another bike. Plastic weld, Zip ties, rivets.
The Mexican Taller guys are incredibly creative. They really think outside the box ... they will help you!
Best of luck!