XRAY - Model racing cars

I recently damaged my chassie plate and replaced it. When I should assmble the upper deck it did not really fit within it's slot between the clamps. I had to press it down and that tweaked the chassie.. tried the other upper deck I have and same problem.
I removed the upper clamps and the differentials and replaced two bulkheads but still same problem. The car gets tweaked about 0.2-0.4mm after assembly of both back amd front screws in the upper deck, measuring at the same place as down stop is measured. I press at the front battery backstop area to see this tweak.
Is it possible that the holes in the chassie plate is just slightly too close to each other? I can see that the holes in the upper deck and the bulkheads is not 100% aligned tho it is very close ( I also feel a small resistance while assembling the screws ). I measured the different holes sizes and there is not much to play with and this makes me think some tolerances dont match..

As said. I changed bulkheads since I thought they might been damaged (2 of them, cannot see any differences tho) and have 2 upper decks. Reassembled several times without any difference.. the upper deck cannot fit nor does it assemble correct even tho I remove the clamps..

Anyone with feedback? I do not have the old chassie plate left so cannot measure them to see any difference.

Edit: filed up the holes slightly in the upper deck and problem got less, also felt the screws easier to assemble, did not have time to do it to a 100% but will this afternoon, cant say I am thrilled about that as a solution tho even if it should work..

When I look for tweak in the chassis, basically this is my process which should work in your case as well:

1. Take out all bulkheads and upper clamps from the car. Put them on a flat surface such as your set-up board to see if they are bent in any way.

2. Put the topdeck on the same surface and make sure that it's perfectly straight.

3. If you can't find anything. Most likely, the chassis has been somewhat tweaked and has to be replaced.

You can file down the topdeck to make it shorter, or slightly enlargen the holes, which I have seen as a temporary solution in the past.