Thanks guys, but I haven't bought that mower after all. I had some trouble with the seller refusing to negotiate at all and having very poor communication so I've moved on. Purchased a (maybe) 12mth old Victa Vantage with B&S 450 4 stroke engine instead. Its running a little rough, so I'm going to drop the oil, check the filter and spark plug and see if that helps.
Throttle also isn't working properly, its catching at the stop position so to get it to stop you have to physically reach down and push it into stop position. I'll have to see if I can adjust it a bit higher so its not catching.