Most of what came about them finding out about me, was from brain haemorrhage. Until my legs started to giveway, I only then started to feel bad. This was caused by high BP (I knew I had it and had not bothered with the tablets for some time) caused by a mixture of stress and too much alcohol. My point being, that until that bleed on the brain, no one was the wiser.
My platelet level is about the same as yours, the reason for which I had quite a few platelet/plasma transfusions in hospital to try and stablise me. My low level is down to my liver, normally low platelet level is down to the liver not being able to absorb vitamin k and therefore produce the clotting proteins.
You talk about your spleen being enlarged, have you had an ultrasound? If the gastro wants an endoscopy, it is because there is something that he wants to check, naybe a pattern he has seen before, a hunch or just to be on the safe side. I would take the endoscopy, it is very good for having a general look inside you, not just for varices. Two tips, one, if you ever get told by a gastro (or any consultant) for this sort of procedure, always ask why, ask them what they're thinking. Secondly, if you have a gag reflex, go for the sedation, the scope is about as thick as the forefinger.
I would doubt you have varices, because as far as I know, they only come with severe liver problems. They are caused by portal hypertension in the liver. On the bright side, mine had gone on my last gastroscopy, so non drinking plus a special beta blocker for it, does seem to do the trick.
I must admit, I am trying to think why your gastro wants to check for varices, but I would certainly welcome an endoscopy. I would also want an ultrasound if you haven't had one. I got a print out on the day, telling me there was no sign of varices, but mild gastritis. If you're not give anything, might be worth asking for a copy.
Please do come back and let us know the results.