Harsh metallic rattle on cold start, and lots of cranking on 2nd start.

Afternoon guys!
Well having repaired my exhaust, which sounded like a tin can rattling about inside a bigger tin can (!!) - I can now hear the engine on startup.

I have a worrying sounding rattle coming from, well, the engine, its a very harsh metallic rattle when cold, almost sounds like a thin heat shield knocking on something, but sounds like its coming from the cam area.
It goes away after 30 seconds or so, and doesnt re-occur on the same day?!

Could this be something like sticking cam followers??
(i have good oil pressure, and plenty of oil)

The car is low mileage and did a LOT of sitting about for the last 8 years, the oil looks rather tired so will change this ASAP.

Second problem I have:
The car starts from cold very easily, crank it over for maybe 2 seconds and off she goes.
However if i start it, pull out of the garage, stop it, do some stuff (load boot, lock up etc) then try to restart, i really struggle to start it again, turns over fine, but takes a good 10 seconds to splutter into life. once its running its fine.
When i stop at, for example tesco, do 10 mins shopping, it will take about 5 seconds to fire.

what could this be? wet plugs? weak spark?

 

Thanks guys! Yes thats pretty much what it sounds like, i'll give it a spray and see what happens
I Hope it is that as otherwise its rather worrying!!

I'll go read the other thread now...