Well i'm new to Pinball myself so i'm no expert. But I am in Grimsby and if you want a second pair of eyes to check things over with you then i'd be happy to do so - just drop me a PM and we'll try to sort something.
A few more things that might be worth thinking about:
1. Did you get a manual with the machine? Always worth having a scan through that but if you don't then it would be well worth trying to track one down. Quite how you'd do that i'm not sure - i've checked Marcos and eBay and they don't have one and there doesn't seem to be a PDF copy on the IPDB. I have a feeling it might be a tough one to track down.
2. Have you got a multimeter? Might be worth checking the fuses are all in good order as it's possible one may have blown at first power up or maybe even damaged through vibration in transit.
3. If you've got a multimeter then you could also measure voltages going to the display board, but that's not going to help massively if you don't have a manual telling you what you should expect to be seeing.
Unfortunately the lack of online manual means I don't have much to go on. When you say the display board is it this bit that's not working:
http://www.marcospecialties.com/pinball-parts/MA-1361
If so then so far as I can see from that image there are only two connectors going to that board. I'd remove the connectors and reseat them and then trace to the other end and do the same there. Hopefully by working backwards you can identify the cause of the problem.
Good luck with it - it's frustrating when you get these issues but so satisfying when you finally crack it.
Cheers
Pete