Sounds very frustrating Norm when you have fitted a new needle and primer cap and the carby still floods.
The mulch plate that was modified is just the flutes on the plate bent to a different angle than standard Mf , the standard flutes point down so you just bend then up with a big shifter. The base in one spot needs a little hammering so the blades don't rub after fitting the plate.
Mowed today for about an hour and 10 minutes ( 1 and 1/8 of a tank of fuel) and the needle and clip worked well, carby didn't flood and the needle didn't get stuck.
One thing not mentioned yesterday was when mixing up 5 litres of 2 stroke , it was getting late and I only had two and a half litres of unleaded left so also put in two and a half litres of 20 year old super fuel to make up the 5 litre mix, the mower ran fine no problems ,I even put the same mix in a Stihl FS 36 line trimmer that I hadn't started for at least 10 years and besides the primer bubble that I had to replace as the old one was solid the line trimmer started and ran well.
Found another use for a Victa 2 stroke Today they work well to mow down an Agapantha you no longer want.