My car has no antifreeze in what so ever by looks of it, I also used an antifreeze tester, one of them floating ball things and none of them floated.
The floating ball thingies, which work on specific gravity, aren't totally reliable - they work well(-ish) with normal antifreeze, but give wrong readings with propylene glycol stuff (which is obscure, I'll admit). For reliable readings on any antifreeze, you really want one of the refractive index thingummies (although, that's probably all irrelevant, because you probably do have naff all antifreeze, if you can't smell it).
its a 50/50 mix of anti-freeze & water
usually between about 1:2 and 1:1,
AF:Water. The UK doesn't reach such peak low temps as some of Europe so you can probably get away with the lower conc (but see whatever the AF supplier recommends on the container), but you wouldn't get away with that in some of the more landlocked parts of Europe.
And also, some suppliers sell you pre-mixed AF, and you shouldn't be adding water to that, so read the instructions.
If you don't know what AF was previously used, you may want to try to get the 'compatible with either type' AF, otherwise you have to bet on what was previously used (probably the standard Ford OAT, but, in these circumstances, who knows?).
Also, be careful what water you use; hard water will deposit in the same way that it would in your kettle, and you really don't want an insulating layer inside your cooling system.