Love that game...The latest set of the rules tis FREE!
https://emeraldcoastskunkworks.wordpress.com/
not actually the latest set of official rules. just the latest set of fan-rules.
the latest set of official rules by the company is
Full Thrust Remixed.
it compiles all the rules from Full thrust, more thrust, and fleetbook 1. the alien systems from fleetbook 2 aren't included but they are easy to add. i personally include the playtest rules and systems from here:
http://fullthrust.star-ranger.com/these are items GZG picked from fan suggestions for the (long delayed) third edition.
Continuum, cross dimensions, and the other fan-versions started with the same base sets of rules (compiling the old main book and supplements) but they have added scads of new weapons, rules, systems, and ship types to the point it makes for a complicated game that almost has more in common with starfleet battles than full thrust. (not surprising, given many of the new ship types and systems in the fan-rulesets seem drawn from SFB and the other trek derived game systems, the point of using any of the same names and terminology)
i recently was able to purchase the mini's i need to complete my tholian and klingon fleets, so hopefully i'll be able to host some games beforel ong.