This the fantastic plastic 1960's NOVA III by Tarheel Industries of Tarboro, USA famous for their Project SWORD US copies.
It's one of three NOVA's that formed a series: I,II and III, II being a pink Thunderbird 3 lookalike and I a green jet similar to the Spacex HAWK.
The main SWORD Moonbase Blog covered the origin of NOVA III earlier in 2009, which you can read here. and on the Space 1999 Forum here. In short, its THUNDERBIRD 6 or at least one Brains' designs - the red craft at the bottom of the picture below. I don't think the other two designs were ever made as toys. Or?
You can see footage of Brains and the Thunderbird 6/Nova III in the film Thunderbird 6 on You Tube
(7.7 minutes in)