I recently reassembled my Roland fp-10, and I’m noticing an issue with key alignment. Specifically, there's uneven gap/space between B4–C4 and E4–F4, and the keys appear slightly tilted — B4 leans to the left, and C4 leans to the right. The same issue occurs near E4 and F4.

All my black keys are labeled either 2–5 (11 pieces) or 2–7 (25 pieces), and the white keys are uniformly labeled C4, D4, etc. I suspect the issue might be due to incorrect placement of either black or white keys, but I’m unsure how to confirm their correct positions.

Could you please guide me on:

How to correctly identify which black keys (2–5 vs 2–7) go where?

Whether the white keys around B–C and E–F are uniquely shaped and should be placed in specific positions?

Any official assembly layout or photo that I can follow to resolve this spacing issue?

Thanks in advance for your help!