Richard,I think you will find it was the Bayko building system,advertised in the Meccano magazine circa fifties ( this centuryTiger ! )
There was another building system that utilised real bricks and morter,whereby you used a small trowel,the cement could be dissolved and the bricks salvaged.
In my collection of historic ( this century again ) consructors sets I have one called Kliptiko,again rods and things,the most unusual one was Junero,this had some clever little bending tools ( still in use in my twentieth century workshop ) you got a sheet of mild steel,rods,road wheels,corrugated panels,some small parker kalers etc the idea was unlike Meccano you had to make your own parts,there was even a useful hole punch,all great instructional toys/models in their day,dont forget we had no computers whatsoever,and despite what people think these items were expensive,purchase tax crippled models and toys after WW2,magazines were booming and sold in their millions unlike today,they were the lifeblood of model building,today in Smiths you see a dozen at the most of model mags,deliveries of for example the Aeromodeller would be in the region of 500 copies to my local model shop alone,once again no internet,the only mail order was people like Henry.J.Nicholls & Roland Scott,they would carry expensive two page ads in the magazines,selling mostly to serving members of H.M Forces who had flourishing model clubs back then.