the msds for parks patch kit shows the "glue" as naptha a(about 75%), n-heptane (20 % or so), octane (less than 5%) and 1-heptene (less than 5%).
I did try the experiment using remo patches and old tube and contact cement. rubber cement, and the conventional glue. The contact cement did not work at all, the rubber glue (elmers) worked at about 80-85% of the peel strength test as the regular tube patch glue. I had an old tin of the 16oz tip top cement- the aromatic eventually escaped leaving me with a cement that was too thick to be used, being in california with the voc restrictions at the time left me with no choice but to toss it. I see now the while I still can't get xylene - which might have acted as a decent solvent to thin the tip top but I see now that I can purchase "bestine thinner " which is heptane- so that might work as a thinner to the next 16 oz can of cold vulcanizing fluid I buy.
I have to have a bit larger quantities of the vulcanizing fluid as I regularly cut (splice) down latex tubes for use in 559 and 406 tires.Used to buy 2oz tubes of cement from niagara cycle but they went belly up and haven't found a second source of the same size.