Dang, I go to work and you guys talk up a storm!
I would love to get you guys a full pic of my gun but it may take a few days since I don't have a digicam

. That sping around the front is a custom made pump handle return spring. All I need to do is pull back

.
As for the polishing, if you are going to be doing a really good job, first start with 400 grit to get rid of burrs. Then switch to a 600 and finally finish it of with 1000 grit. Then take some good metal polish to it, preferable something made for brass and aluminium.
I personally can't say I'm a sniper since I play as a frontman in speedball with my setup. I can tell you right now,
I RULE the snake! With my setup I can hit a pie plate 9 of 10 times at 100ft. That's about as good as it gets for accuracy.
As for being the best you can be, there are a few things your gun needs. I'll esplain each point as we go.
1. You
2. A good barrel
3. A way to aim it
4. A hopper
5. A co2 tank
1. You
This is pretty obvious, but many people overlook it. You need to be a good shot, the best gun it the world isn't going to matter if you can't be a stable shooting platform.
2. A good barrel
A good barrel and paint to barrel match is key to accuaracy in any gun. I've pesonally found that a cp .689 fits marbs perfect and they in turn fly true for me.
3. A way to aim it
You need some way to point the barrel where you want it every time. The easiest way i've found is a cheap red dot sight made by adco that you can get at Walmart for $13. Another good one is a fiber optic pin made by BE or Daisy (I can't remember) that costs about $3 at Walmart.
4. A hopper
Some where you need to put the paint in.

I personally like either 15 rnd direct feed tube through the powerfeed or a 15 rnd stock class tube. I like small hoppers cause your gun is therefore lighter and faster to aim. Not only that you can run a hell of a lot faster with a lighter load of paint on you.
5. A co2 tank
Yes co2, not hpa. Co2 has a few advantages for pumps the primary of which is size to shot number ratio. A small 4oz tank of co2 can give you 400+ shots on a pump, while any hpa system will be considerably larger and heavier. Co2 is also much, much cheaper and since you are playing pump, you aren't looking to spend much $$$. Also, if you use more than 400 shots in 2 hours of play, you should be looking into a semi cause you're using the autotrigger WWWWWWWAAAAAAAAAYYYYYYYY too much.
I hope this all helps you out.