Old lawnmower acting up?

I have an old but excellent Qualcast/Suffolk Commodore , it's been running beautifully till last week when it refused to start, Did all the obvious things such as cleaning spark plug checking for dirt in fuel.Took off float bowl checked gasket all seemed to be ok.Noticed when I tried to start it fuel was coming out of small hole on float bowl, going to replace bowl gasket(if I can get one)
Any suggestions would be much appreciated.
This mower has a Zenith carburetter 13TCA-2