Tough call because they are so uncommon,and they are Slings.Not a lot of other sold examples to measure by either.
On one hand,a club date kit with matching snare and a couple of A Zils and cases 1200.00 would be fair.Slings usually go for less,as far as top line series go.
It looks like that kit is a 20 12 16,would be worth more if the FT was a 14,and the snare,if a 6 lug is a 125.00 175.00 drum,which it could be considering that is a lower line kit,if the snare is 8 lugs it is worth more.
But that is a terrific looking vintage kit that like the others say you don't see very often.
Like others said the rarity could go either way for the seller,If I wanted them and had the money I would not feel ripped off if I paid 1200.00 ish,but I love the way the kit looks and it's mojo,and I love that finish on that set,but if you thought you might want to sell it sooner and get 1200.00 1300.00 I don't know.
Maybe you should make non insulting offer,I think 1000.00 would pretty fair on both sides, IMO.