Hey guys, pretty new here, had my 1991 Golf Clipper for 6 months now, its not been on the road yet as im sorting a few bits and bobs for summer

Anyway, hopefully someone will be able to help me.
The problem I have is, my car pumps out a cloud of blue smoke on startup, but only on startup, and usually only if it hasnt been used for a day.
It was fine when I bought it, and it only started smoking after I used an engine flush.

Oh and I also get a top end rattle now, which usually dissapears as the engine heats up.
Any idea's how to fix it, and what do I need to buy/change.
Thanks