Just my thoughts but... do really any etnic group decide the future of a piece of land? In my opinion no.

If I gather a group of spaniards, go to some unhabited piece of coast (for example of France) occupy it and stablish there... do I have any right to claim self determination for it just because I live there?

Remember that UN made a resolution in which it call for a descolonization of Gibraltar.

In my opinion the solution is pretty simple: Make a long term agreement of co-sovereignity, let gibraltarians choose their nationality, respect their properties and current rights, and let british make use of any militar bases needed. That way everyone should be happy.

Fernando