I think you will find that as you attach the siderails, it will become evident that the pattern (as seen along the bottom edge of the siderail) is not sitting right comparing old and new.

For example, on your Fathom near the right hand side flipper button, there is a painted section whose top edge is traversing across the flipper button hole.  On the original paintwork, the top edge of this same section is well below the bottom edge of the siderail edge.  It's out actually by quite a bit.  And I think you will find the same for some parts along the bottom edge of the left hand side siderail (example of this is the painted section near the rear set of two bolts - the top of this section will sit below of the bottom edge of the siderail, whereas on the original this top edge was mostly concealed by the siderail).

As for the front, even though the image I provided was not square, it does show a large gap between the two painted sections (in the circled area).  On yours, the image you provided of the original paintwork also shows a very similar gap.  On the now painted Fathom, they are virtually touching.  Again, quite a bit out.

Again, I will certainly recognise that Fathom would be one of the most challenging stencil sets to come up with.  I looked at the pattern again last night, and it would give me a headache just even contemplating tackling it.  Hats off for sure to Gavin for his efforts, and as always Nino, you do amazing and very thorough work to be commended.  No disrespect at all.  But, if my comments are correct, then in my opinion there is still improvement that can be and should be made to the stencil.