That tin drum set looks smart but you are paying £45 odd for a steel can. Ouch !
In answer to the questions above:
The Flo Plast fittings I picked up a couple of years ago from (probably) B&Q or Screwfix say 48mm WS08, BS EN 1455 B CS, and ABS on the side. Now you know as much as me
. Mine look just like the ones in your link but the white ridge around the middle is on the inside, not the outside.
The thing that matters though isn't the inside diameter of the fitting (or maybe the ID of the pipe they are meant to be used with) which is what the 48mm will refer to, it's the coincidence that these fittings are a slide fit INTO the dust commander connections and a loose but not sloppy fit into 50mm acquarium hose. They just let you join two equal sized pieces of pipe together. In practice I clamp them into the hose and just slide the white ends into the cyclone.
Buy the cyclone then just take it down to B&Q and your local plumbers merchants and try things to see if they fit
The trick to fixing the cyclone in the lid is to make a stack of plywood rings and another bottom about 4 inches below the lid. The whole thing looks like a stubby top hat, with a hole in the top, dropped upside down into the blue barrel. If you figure out your dimensions, the cyclone screws into the lower piece of wood like normal but is supported all round because it's a snug fit where it passes through the bigger disk.
You can still knock the barrel over but now you'll never damage the screw connections around the lower opening of the cyclone. Adds a bit of weight too, to resist the pull of the hoses.
