Don't you mean Sou'wester?

For what its worth my 1971 copy of Pooley's lists a large number of aerodromes with Aeronautical Light Beacons, picking some out we have

Southend White/Green ( no code )
Luton Green coding LT (behind the Tower if I remember)
London Heathrow Green coding LH
London Gatwick Green coding GW
Hatfield White / green ( no code )
Cambridge Green coding CI

Details of ABN/IBN for individual civil airfields are in Section AD 2.15 of each airfields AIP entry.
When Niknak mentions '3 letter ICAO codes' I believe he's getting confused between ICAO and IATA; IATA codes have 3 letters, ICAO codes have 4. He mentions 'HUY' which I believe (don't know much about IATA codes) is the IATA code for Humberside. Humberside is not listed as having either type of beacon.

IATA-Code: HUY
ICAO-Code: EGNJ
Location: Kingston upon Hull
Airport: Humberside
Country: United Kingdom

Humberside had a beacon until 1998 when it became too expensive to keep serviceable. It was a "punditgreen" coded "HS".
Pundits nearly always had a bigraph code which corresponded to the i/d letters in the signals square. AFAIK they were never coded to the approach aid nor to the ICAO "last two", unless these corresponded to the signals square.

PG

Yes, yes, yes,
- But why were they called 'pundits'?
Saw the Heathrow installation in '68. Allegedly visible from 30,000 over the English Channel.
EGNX had an aerodrome light beacon, flashing green ('Charlie Alpha'), between the original tower and the grass strip, (01/19).- about where the current ATC facility is sited.
EGCC had a green beacon in the '90s, which superseded an ABn on the hangars north-east of the tower.
EGBB had a green and white ABn, in the early 1970's.

The Luton beacon was indeed behind the Control Tower. It was on the roof of a building on the approach road. I can't remember what the building originally was (before my time), but it ended up as something to do with Vauxhall.

The light went when the building was demolished in the early 70s, if I remember correctly.