Model Railroading > ? about building Campbell kits

I am starting on a Campbell Northern Water Tank kit - my first time building one of these wooden wonders. Inspecting the parts I noticed the siding sheeting for the water tank and below that has a bit of an arc or bend to it. It is thin wood, milled to replicate water tank staves or lap siding.

Is this arc or bend anything to worry about?
Does it straighten out as it is glued to the more substantial innards?
If I have to fix it how do I do that?

Expanding my skill set,
Clarence

I have made over 40 of the Campbell kits and all of them are awesome. Some times the wood is not as straight as it should be, so I just dampen the wood, and put weight on it to flatten it out. I let it sit for about a day or so, and usually things are alright. Wood is so forgiving, that you can't hurt it with some water. Hope your kit turns out well. Take your time, paint or stain before you glue anything, and you will be satisfied. Enjoy!

On further review I think the arc is "normal", at least for the tank wrapper. It has to be flexible to bend around the tank form (some stout cardboard). The siding sheets on the enclosure under the tank might be a different story.

If I did want to straighten out the siding - how damp do I get the siding?
Heavy - Toss it in a pot of water?
Medium - Paint it with a brush?
Light - Spritz it from a spray bottle?
Both sides?

I've read the instructions several times and it seems straightforward enough, but time will tell on that.

Thanks,
Clarence

Start with a spritz from a spray bottle and see how pliable it becomes.