T5's only work with the V60's as designed. The connectors do not fit between ecosystems.
Comm Gear Supply makes adapters that will allow you to use other headsets (ie not the X5 bone conducting earbuds) with the X50, but they are prevented by Invisio from doing anything with the V60 ecosystem of PTT's. (Last I checked this included T5->X50 adapters as well)
The radio-side of the PTT cables are also different between X50 and V60. Invisio will not sell to civilians, and their dealers are prevented from selling V60 ecosystem products to civilians as well.
There are some grey market sellers on eBay that you can find cables from, either Chinese manufacturers, or grey market Invisio cables. They are very expensive. Your options are really either to stick with the X50 ecosystem and purchase the requisite adapters from someplace like Comm Gear Supply, or go with the T5/V60 ecosystem (which is great btw) and spend a grip of cash on potentially iffy cables from eBay.