I've just managed to track down a 'customer' that owes me a few thousand from two years back. Can I still have him in court?

probably, I think the cut off is six years?

I've just managed to track down a 'customer' that owes me a few thousand from two years back. Can I still have him in court?

Assuming as part of your contract with the customer you have not agreed to a shorter limitation period, then yes 6 years is the (usual) statutory limitation period for claims under contract.

Compile all information you need to demonstrate that he owes you the debt and that you have done all you can to mitigate the loss and then issue a letter before action requesting payment. Give the customer a reasonable time to pay up (7-14 days) and then issue proceedings in court.

If it's less than £5,000 you can go to the small claims court, and don't need legal representation. Higher, and you go up a "level", and prob do need a lawyer. Get one to advise you on a fixed fee basis.

is he still trading as the same company ?

No he isn't, he was a sole trader.
The original debt was 6.5K and he paid some off. The payments became smaller and smaller before he disapeared.
It's 1.8K from 2008, the original debt went back to 2006.

prepare for the possibility that you might have to spend further money enforcing the debt even if a court order is made.
my brother had this problem against an ex landlord.