Check the rudder blade and centerboard. Both appear to be homemade. Check the plastic rudder cheeks for cracks anywhere and everywhere. An ‘83 came with aluminum cheeks so what’s on here is a replacement. Be sure they are ok. Be sure sail looks ok unrolled.
Yes; if it's pretty bad, there will be standing water (bring a flash light).
Also, touch the Styrofoam panels with your fingers (or a piece of kitchen paper) and especially the 'glue' that holds the panels in place. That stuff really absorbs water.
You should also bring a scale and weigh the boat; proper weight is around 130 lbs. You will need another hand with that.
The boat should not weigh more than 135 lbs ( correct me if I'm wrong guys). The foam support inside can be dried out because it has the inspection ports though. You could bring a bathroom scale and weigh it by tipping it on it's side and setting it on the scale-bring a friend. Check the bottom of the hull for any cracks etc. There is a huge amount of info here on the Forum about fixing and updating used Sunfish so you are in the right place. (Also, what Wavedancer just said)
The ports mean that someone has been inside the hull to repair the hull or dry it out, not bad in fact it looks like someone has worked to keep her sailing. The stand up block is an upgrade as far as I know, and as Beldar mentions the daggerboard looks hand crafted but good to use.
As far as I know the hull weight did not drop from 139 to 129 until the 1988 move to the rolled edge boats. Even if she weighs 139 + a few pounds she will sail well.
$500 is a good price as long as the sail is in good shape, no rips or ugly repairs or dry rot, and the hull is not waterlogged.
I had a 1983 in that color scheme that weighed 121, and a friend’s weighed 119. That is back when I was a serious racer and paid attention to these things so I am sure about those weights. My 1983 is being raced by someone else these days. I should weigh it. It’s had some leaks and repairs so I’m sure it weighs more, but I should find out.
Not necessarily... I routinely install inspection ports in my sailboats ANYWAY, they're good to have and they help air out the hull when the boat is not in use (condensation in storage, for instance). Clear see-through hatch covers are best, you can check at a glance while under way to see whether the boat is taking on water. You'll also feel the boat get sluggish if this happens, but it's nice to be able to quickly glance at the port(s) for peace of mind, LOL.
I like the second boat better, the one with the North sail... I take it neither one comes with a trailer? Maybe you don't need one if you're gonna put the boat on a rack at a club or whatever. The first boat looks okay, but the second would be my choice since it's *only* $200 more, and ya might be able to knock down the price a bit if you're paying cash. Remember, CASH IS KING!!! LOL...