Reconstitute Additive F ?

So I have an old-ish plastic bottle of Additive F that has obviously lost something as it is about half the volume of the container and is fairly thick.  I’m thinking that Additive F lost its xylene.  Is that an accurate assessment?  And if so, can I simply add back the xylene to make the Additive F whole?  Thanks.

The MSDS sites xylene at 85% and non volatile/hazardous solids at 15%, which are maybe hydrocarbon waxes? Anyway, as you’re aware xylene has a habit of evaporating. Don’t see why it won’t work. 

Yes, worked perfectly.  I transfered from the plastic bottle to glass bottles/jars.  Thanks.