Flymo petrol lawnmower

ive recently brought a second hand flymo petrol self powered mower, I need to buy a new drive belt for it but the previous owner decided to re spray the deck and cover any model number markings!!,    All I know is that it is front wheel driven and it has a Briggs and Stratton Quattro 4HP engine, 

ive looked on-line everywhere and cannot find one that looks similar, 

if anyone has any info it would be greatly appreciated 

many thanks 

Kev