5 HP Mercury 2 stroke questions

I have an older Mercury motor. Does it have an impeller to pump water in the leg?
What year do you think it would be? Serial no. is 0D932373
In the second picture showing the leg there is a couple holes. Only air is coming out of them. Should that be water?

I changed my water pump and impeller in my 7.5 HP 4-stroke Honda but I have not worked on this 2 stroke before.Thanks for any help you might give.

Yes this model has a water pump (impeller) located in the lower unit (same as your Honda).

Those holes in your second pic are called "exhaust relief" holes - they may spit a bit of water (should get a bit of mist on your hand if you hold it in front of them when running) but are primiarly to let exhaust out - I don't believe there is any "tell tale" (pee stream) on this model (I have a 1987 twin cylinder 2.5 horse Evinrude that is the same - sucks not being able to "see" that the waterpump is working - so I look for a "drizzle" coming from the exhaust relief holes on my model).

Here is a parts listing for that particular model:
http://www.marineengine.com/parts/mercury-outboard-parts/45/0a855097-thru-0g710612-usa

Thanks for your help.
I noticed two good streams of water going out from the prop area when I ran it in the barrel yesterday.

I'm new here and not sure how to get my question posted, but does anyone know much about a 1981 merc 7.5 outboard?