No real need for a scan with such simple geometry.
Screw a partially threaded bolt on the top, stick pins on the bottom two + the crank and mesure all distances and diameters with long vernier calipers. If you're not good with CAD software and want a .DXF file I can make you one at work around next week.
If you bridge the right pins on the relay connector you can quickly test the fuel pump.
More than the relay it could be that your ignition is the one that isn't working. The tachometer, ECU and tach relay all need pulses from the ignition coil to work.
More modern conrods are usually lighter and perfectly fine for the job but the downside is that they won't survive anything more than that.
Old XUD rods can push the pistons against the valves and obliterate the camshaft without bending.
Aftermarket pumps may not be as good as OEM ones, at least some are not machined the same internally.
Maybe this pump wasn't too bad inside after a slight surfacing on the pickup side.
The current 508 SW is no 504 but if you want more room and cargo space Peugeot will gladly sell you a 5008.
The 508 SW is using the 5 door fastback wheelbase and not the longer ones from the chinese 508L, DS9 or 5008. Peugeot probably want to sell wagons to those that like the small and sporty 508 but don't want the low roofline from the fastback.
You can look for Citroën XM wiring diagrams, the engine and ECU should be the same:
http://doc.aqrweb.org/Moteur_PRV_24S/Citroen_XM/XM-V6.pdf
https://citroen.tramontana.co.hu/en/system/files/circuit_diagram.pdf
There was no valve seals on old engines, in France the XUD7T started using them around mid-92 (XUD7T/L) and the older engines with seals are the "clean" ones with EGR and cat.
Dual springs means the engine was made before late 1988 (around october for XUD9 and decemeber for XUD7).
250, did you go with the top of the line PSE? The 225hp hybrid is at 240 and the 180 at 230km/h.
As a plug-in hybrid if you want to keep good performance and low fuel consumption you need to charge it as often as possible.
Once discharged the big battery turn into dead weight.
Unless it's a very old camshaft or one from a XUD7T/XUD9SD it should be the same cam profile for both N/A and turbo, even the DW8 was no exception. The other variation is on the end of the camshaft: either machined for pulley(s) or direct drive for the vacuum pump.
It's not just prechambers, the head itself is also craked.
Some say that the tweaks made by PSA on later engines to keep them emission compliant with 90hp also reduced durability.
At least it is sure that R&D was much more focused on the next direct injection head for the HDI as emission rules and market trends made direct injection kind of mandatory for new turbo engines.