No problem a Norwegian owning a yacht registered in the UK. He should also be a UK resident to qualify for UK reg, but many "get away with" simply having a UK address - but sounds like he didn't carry on with the UK registration (or anywhere else?!).
Part 1 registered is better than Part 3, but neither is 100% definative proof of ownership (they are not US style "title"). Ownership is transfered simply by Bill of Sale
, which are of course not registered anywhere. Also no requirement for liens on boats to be registered (part 3 has no capacity to register, part 1 has - but no requirement for a lender to use it!, albeit my understanding is that if they do not it can affect their ability to enforce a loan - not always, but sometimes)....what happens is that a Vendor declares in the Bill of Sale
that the boat is sold free of all "Liens & Encumberances", and if that turns out to be untrue then you get to hope that the Vendor still has some cash! In practice with UK boats not a biggie as commercial
lenders would require a boat on part 1 with their loan registered and mechanics liens etc are not commonly secured on boats (as appears the norm in the US).
If the Norwegian has not transfered the UK registration into own name after 13 years then it will have lapsed on both Part 1 and Part 3 so the boat is unregistered in the UK (and no requirement for a UK boat to be registered - although whether it is still considered a UK boat if the Norwegian is not (never was?) a UK resident and the boat has long since left UK waters is a good question!......would be interesting to know how the boat has moved between countries over the years, if it has?!).
Even unregistered the Norwegian still owns the boat of course!, his proof is the bill of sale from the previous owner. For the Part 1 register it is possible to "re-activate" the registration after it has lapsed (but need the current and the new owner to qualify for UK reg by being residents)....how long after it lapsed you can do that I am not sure - will need to check.
Not familiar with Canadian Reg requirements, but I would expect that they require evidence that the boat is not on any other register - lapsed should count! (and should be easy to prove)as well as not being on any register!....will also likely need Bills of Sale back to the last owner who was registered somewhere (and proof of that - transcript or old / expired reg document), in an ideal world also back through all the owners to new - but with older boats those tend to go walkabout.
If the Vendor has the Bill of Sale into his name from 13 years ago (plus details of the UK reg INO the PO - now expired) then you should have enough to work with - and IMO after 13 years a pretty good chance that it is his boat (the PO probably would have challenged ownership by now, so odds are strong that the Bill of Sale is good), although of course he could have sold it 5 times already last week!, but with a Bill of Sale in your name, a valid (canadian) reg in the post and possession of the boat (being 9/10ths of the law!) then you sound good to buy.
Obviously you do need to check that the above info is good! and exactly what paperwork the Vendor has - a simple receipt on the back of a fag packet from the PO is not a Bill of Sale!, albeit it could be worked with........