I have to rev it a few times, before it goes into gear

Hi..there..

If you havent done so already - check you gearbox oil level..you should have dipstick for it..if i recall on the drivers side of the engine bay..its grey/bluish dipstick ring pull.. take look at the oil and condition..if it smells burnt/looks black then its an internal issue - if its creamy looking then you oil cooler on the main radiator asblown and coolants entering the gearbox oil or vice versa..not good as that will eventually damage the gearbox beyond repair..ideally if the gearbox oil has never been done for while then it be certainly making that a recommendation from here..as that will give you a better idea on oil condition once its dropped..the sump pan removed and then the filter element taken out again checking what the filter is caught will give a good indication as the health of the gearbox..metallic debris or fine particles would mean the possibility of another gearbox..