Ah, I got the image in my post now.
The line, float and weight setup looked exactly like this but in my younger days it was just the reel line straight through to the hook and normal shot. The float would be about a 6" peacock quill and the hook a 12 or 14 with maggots or a piece of lobworm as bait. I don't seem to remember overweighting the float either, just the weight required to cock it but all together a foot or 18" from the hook. I always used this method when tench fishing and it was very effective with the float sometimes lying flat, or cocking or just sliding away altogether.