I agree with @Old_Grey on this one, I don’t think we will find another hall sensor with long leads in a smaller case these are already pretty small. As well you have used these (at least I think you have used these) and they work, a new one may not. So I’d advise using these ones.
That’s good, at present for the right side (at ~6.1 mm spacing on the sensors) it takes 296mm from the start of the first sensor case to the end of the 49th sensor case so you have a few mm left over. Given the long leads on the sensors you should be able to place move them a bit left or right to line up if you need to. I’m going to finish up connecting schematic for the right hand board and then I’ll clone that and move the sensors for the left hand board. If you load the accordion-Sketch.fzz file in to fritzing in pcb view you can look at and measure (and change if you like) where the sensors are:
Here sensor 49 is selected (by clicking on it) and its position shows up in the Inspector window on the bottom left. X followed by Y in mm (circled in blue). If you click on mm it will cycle from units on inches to mm to px (90dpi I expect). If you change the numbers in Inspector the part will move to the new position so you can custom position each sensor if you wish (if that would be useful). To see the spacing, record the x coord of u49 then select U48 (the next sensor along) and subtract its x coord from that of U49 and you will get about 6.1mm (it varies a bit from sensor to sensor by a little bit depending on the snap)
If you don’t want mounting holes, that is fine, it is just that it is easy to add them to the pcb and saves you from having to drill them in the finished board. It isn’t a problem to leave them out if that suits you better.
I use Snippng Tool on Windows (it is in the accessories folder). You pull select an image by pulling a box around it, and it creates an image. Then it has a pen tool in the tool bar, where you can set the ink color (default blue) to red and draw on the drawing. Once that is done you can save the image as a png or jpg image for upload.
Peter