I popped over to a friends yesterday to get him to give his opinion on my chain & sprockets. He's a car mechanic but does have two bikes himself though prefers to let a bike mechanic maintain them so he can just enjoy riding them.
He reckons it's still the original chain and whilst there are no signs of hooking the sprockets teeth do look quite open and that fresh sprockets and chain wouldn't do any harm. So I'll speak to a chap he recommended and see what the damage is as I'd prefer to get it done properly and for the sake of £40/50 I'll know it's right.
I did however successfully complete an oil change today & replaced the filter too. I struggled to get the old one off. I tried with my gloves on, gloves off, belt as a make-shift wrench and ended up picking the front end of the bike up! I had a monkey wrench out the back which just ended up denting and crushing it so I ended up using the method of a screw driver and a hammer, except with a chisel. It was on very very tight.
Luckily the replacement has a nut fixed on the top so should be much easier to take off.
Supposedly serviced 500 miles ago the oil tells a different story..
I appear to have over filled it slightly

as the bike is upright but isn't level whilst on the Abba stand, I was scratching my head as all 4 litres went in. Dry capacity was 4.0L, Oil change only 3.4L and Filter replaced was 3.6L.
Am off in to town anyway this afternoon so will leave the bike at home until I have removed the excess via syringe .