I have a Jurupa in third year.
Mine is healthy,but did not produced any fruits.
I think from my experience that most of the time,what we think that is fig mosaic virus is only stress due to,soil,climate heat cold etc.
The simptom of disfigurated leaves are the same for stress and for fig mosaic.
On the other hand we can rationalise that all old fig cultivars ,being grown from cuttings had a chance in their history to aquire the virus,so most cultivars have it.
So your best Remedy:give it what it likes,a little fertiliser,alot of compost and manure around the tree,and not deep in the soil.
It should come out of it or grow a new healthy trunk from soil level.
Then later when the new trunk is strong enough,cut down the sick trunk.
You will end up with a new healthyer tree.
And try to grow a succesfull fig next to it so you forget about the frustrations with this one.
For example :How many fruits I could eat if I only grew Black Ischia in my back yard in the last 5 yrs.
Answer:about 5 very tasty figs.
But I grow Marseilles vs black,wich is very good but one class lower than Black Ischia in Taste,yet I made 65 ,10 ounces jars of fig jam last year also from a 5 yrs old tree.
I hope this will help