I'd suggest considering the following:
Old tyres don't seal well, so you may find it difficult to get the tyres to hold pressure until you invest in new tyres.
Some tyres are too loose for ghetto tubless, and will pop off the rim when ridden, in my experience Panaracer fire XC popped off the rim twice on it's first outing with Joe's Tubeless, I'm thankful that it was the rear tyre not the fron, seeing as it was the black run at Llandegla that this happened on. Ended up mid ride converting that rim back to tubed in the middle of the forest, not difficult, just annoyingly messy!