As an update to this, the user @
ooyer appears to have been an alternate user name for @
dave0w who has also been receiving items, claiming they were damaged/incomplete and demanding up to £100 of a refund. We also know that this guy is involved with a UK retail outlet and gets parts at cost, yet he appears to be asking retail prices as a refund. Starting to think he's another Jamie Walker to be honest. I haven't named the outlet yet quite deliberately, however I have ZERO problem in doing so, the bad publicity they can deal with themselves.
I would suggest anyone in future receiving a PM stating that goods have been received in bad/damaged/non working condition the easiest resolution is to ask for the item back and fully refund the payment. Yes you may be stung for postage again BUT it's cheaper and a lot less hassle than having no item and being hit for a fraudulent refund as well.
DYE, Eclipse, Smart Parts/GoG/DLX and Empire all have excellent customer service. If you have sold a marker which has suddenly and mysteriously become broken or whatever in the post, give any of these guys a call and they'll sort you out with a service and price for repair.
If anyone else is having or has had issues with this guy please let me know on this thread the details so it's all in one place and I don't have to hunt through PMs.