Indeed! Or replaced CFL with SON.
The fact they are painted in two-tone green also suggests that the columns may be older... The last time columns generally got painted were the 80s up until the early 90s with very very few exceptions after...
I'd assume those Trafficvisions are not more than 10 years old?Certainly by the mid 90s plain galvanised columns tended to be used, those columns look to be early 90s - I suspect the concretes may have went around the turn of the decade.
I know double bracket concretes existed on Churchill Way North (between the A30 and A345), the replacement columns there are newer than those pictured, and are galvanised rather than painted and have SGS203s as the original fit.
It is possible that the TrafficVisions on Southampton Road were original to the columns, the timeline for the introduction of the TrafficVision would fit if the columns were more towards the mid 90s and if that is the case, they were probably some of the first main road SON lanterns in Salisbury.