Phill B

JLCPCB, PCBWay, or most other PCB makers will make you a new pcb. The prices are very reasonable. I've had a good many multilayer boards made for me over the years for various projects. The flexible Land Rover ones are very basic and shouldn't be a challenge for them.

Clown world

Kayfast or Spalding Fasteners on eBay. Best price for stainless steel in my experience.

If you're not towing a lot, or off roading, I wouldn't bother.

I'd say no. The 300 without the EGR had no ECU so everything was set mechanically. Yours does have an ecu so it should compensate to some degree. Basically, if it runs well with no smoke, don't play with the pump

Yeah, I used a similar diagram to that. The B Line was correct on the left rail, off on the Right. And the tub support dimensions were as they are in the diagram, give or take a mm or two.

Could be a number of reasons why yours is off. Mine was off ~7 mm too. Twisted chassis from offroading, accident, etc. Too much heat put into the chassis from welding, supported incorrectly while welding. I think mine was from the previous owner over-welding. Professional welders tend to break up welding jobs so as not to put too much heat into one area at a time, DIY'ers tend not to consider that I think. I corrected the right rail twist on mine by removing the left rail axle stand and welding. It then bent back to shape due to the weight/heat put on it.

Welders etching fluid can bring out the serial number. You'd have to rub it down to bare metal. Even if the number is no longer there it can still show it. Police also use it to show chassis and engine numbers ground off.

Like you say, do it yourself. You can buy the potting compound at any electronics outlet, Amazon, eBay, etc. https://www.ebay.co.uk/itm/125734829206?hash=item1d46613c96:g:NKsAAOSwOIFjz3QA&amdata=enc%3AAQAIAAAA8Nx0ATEX8X4dMCLuuhUNZmRBU%2FemLO3UKo8eyN8ywh5EW7XJThJzYYpLEqR5jqHgplqu1m6hF6BnLYiqMhFTIG8zrz%2Fy7rfP%2FV9TlBHKlkC5I2UOsyVQf1n%2B%2FwAR3QxmT0xk7Qw%2FlM0UaZcVxFmvLxg22lp0SWTQodQenKY4czYPJuYtlTsquB4gKNDHXwIw2NDlz%2BR1ubJe8Pkolk%2B3mNkvyOIsEInHE7t%2B%2F8nNwkWMR1TESkqUclJ6nwzK9xWVg2t5nK5havSjgDc%2FlanpMwz7cWrpM2TaLG%2B0Jky4UGWsC5ub0tWtKIFE2l0rb1bn4Q%3D%3D|tkp%3ABk9SR_zNpbCIYg

Never seen them for sale here, only the USA. You can get them made for you in the UK though. Hosetechnik, Revoworks, etc

My advice is 111% take someone who knows Defenders. And I mean someone that really knows Defenders, not just owned/owns one. In hindsight, I'd have gladly chucked a ton to someone from one of the LR forums to go with me if needs be. It could save you a bucket of money. /2 cents

I hated doing that job, even with the floor out. You built the mud traps back in though. 🤔

It happened to me. The bolts stripped the threads in the aluminium and I had a brown pants moment. It was like this when I bought it. Loctite didn't work on the other threads, which weren't in great condition either, so I JB Welded the bolts into the alloy on every bolt. That worked well. I ended up replacing them for steel spacers eventually though. Load bearing steel into aluminum just didn't sit well with me.

Ha nice! I use the JBL Flip in mine. Just squeezes into the dash behind where yours is quite nicely. Hooked up to a USBC cigarette charger.

This help? https://youtu.be/km3f-2A66lk?t=1000