Hi re-pm I'm willing to help (but this is your AU so do tell me to shut up if I get in the way I will not take it badly
).
If I was the FI,
1) I would do it on the cheap (GB always does
) so looking to deter an invasion rather than really fight it.
2) when does your AU diverge ? (if its pre 1945 then I think forget about 82 and just plan a story line from 1945-2014, yes you can have an invasion but its unlikely to be exactly the same time/date/size)
3) Use the fact that the FI will be part of a greater alliance, ie GB/commonwealth so kit should be from GB or NATO stuff.(this can cut cost as FI can just use GB repair facilities, say they 'pay' for a number of helicopters but operate them in a mixed pool with the RN this will save on having repair/training facilities etc.)
4)I would use a single big airbase/international airport (at Stanley or nearby I presume it is still the capital + it has a good harbour) + a few heliports/internal airports for light aircraft (5/6 ish one for each minor settlement ) (ie mix use of civilian/mill to cut costs) + any offshore oil rigs heliports ?
My ideas for a FI mix would be (sometime in 70/80's depending on budget/resources and how hostile the Argentinians are),
Army - 1 FIDF/RN commando + some extra support/HQ (700/800 men mainly local reserve with about 300 regulars on rotation from GB)
Ships - a few (2-6). A mix of low (OPV/type 14) and a few high (my 41/61 or even better if you have your budget your guardian or a full on new type 42 ish ?) the high ship may not actually be used to guard the FI but just pooled with the RN.
Air – I would use RAF/RN stuff (and in small numbers to cut costs)
1 x flight (6) of fighter/bombers (I would used phantoms if costs allow if not any cast off's from RAF, maybe swap with harriers if you want the plucky VTOL jet to 'prove' itself just as OTL).
1 x flight (6) support (4x Short Belfast/or C130 but I like the Belfast’s range + 2x Nimrod) for transport and reconnaissance, second hand from GB.
1 x helicopter squadron (mix Sea Kings (mix of ASW/transport) + smaller Lynx/Wasp (for ships with small flight decks)
+ civilian helicopters (from oil industry/internal airlines) will be organised to be available to move troops in an emergency.
+ If you still have any cash maybe a flight (4-6) Harriers for if your main runway is being repaired
(but I would build at least 2 with big taxi ways anyway as there are not many divert airfield nearby).
I would not bother with coastal defences (guns/missiles) as the FI is just to big to cover all of it with a realistic force. I would use the fighters/Nimrods to kill any invasion with Sea Eagle missiles.
OK, maybe a small number of AA guns/missiles to guard the main runway would be useful (I would go with the same as used on the FI warships (land Sea Wolf ? Or just use RAF reg kit).
The type 15's are WW2 hulls they will be to old (and badly made in wartime). I would not use caves (as sheds are cheaper and can look like the many sheep sheds
).
JSB