I recently received a Winchester Model 94 that my uncle Joe had and used for many years. The gun is in nice condition for its age. Probably made sometime in the 1950s.

When I compare that rifle to the one I had when I was in high school, it seems plainly evident to me that the factory put the front sight on crooked. When I compare Uncle Joe's rifle to mine, I definitely have to tilt the rifle to make it feel like its right. And it consistently shoots high and 3 to 4 inches to the left. I wish I could ask Joe how he managed to shoot all of the deer he shot all of those years with that rifle.

So, is it difficult to remove that sight and put it back correctly without marring up the gun. What is the proper way to check to see how far off level the front sight is?

Check your extractor slot alignment to see if the barrels screwed on all the way. But that is unlikely.
Because 94 Carbines have the front sight ramp forged with the barrel until some time after WW2. (Possibly about 1950, post war thing; they did produce 94s during WW2) Anyway check for a forged or soldered front sight ramp.
How did your uncle kill all those deer? I hunted with those guys in action in the 50s. They were mediocre shots with sights, and just used these carbines like shotguns; pointing them at deer and killing them up to 100 yards quite effectively. The 94 was the standard deer rifle then; scopes and bolt actions were laughed at. (My 94 had a peep sight, a Williams 5D, which, for all you kids, means Five dollars)
OH, check level with a, level on the receiver and the ramp top.

Looking at the serial numbers I got that bass ackwards. I thought my rifle was the younger of the two until I just checked the serial numbers.

Mine, with the square sights, is 1,809,XXX and his, with what appears to be (to me) crooked sights is 2,477,xxx. I bought mine used in mint shape when I was in high school, and just assumed that since he was a lot older than me his rifle was older.

Anyway, it appears to me that the front sight base on mine is integral to the barrel, and it also appears that his front sight base is not.
Also interesting is that while both of these are carbines, his barrel is about 1/2 inch longer?

Carbines will have 20 inch barrels. Looks like his needs the front ramp moved.