I would ask here.
https://www.gov.uk/general-register-office
I got several certificates when I was researching the family history and they were sent by post to me here in Switzerland. They’d be able to tell you if you can get originals or certified copies.
I’m surprised to hear this since we did our wills a few years ago with a notary here in Fribourg and didn’t need any of those far as I can recall. We just did wills though, no power of attorney involved.
Getting fresh birth and marriage certificates should be relatively easy:
For Scotland see here:
https://www.scotlandspeople.gov.uk/c…tes-and-copies
On top of that you might need an apostille which you can get here:
https://www.gov.uk/get-document-legalised
For the power of attorney, could you simply complete a hand written poa? I’m not sure if the procedure is the same in Fribourg but in Zurich you can simply write out a full letter stating who you’d want to be poa. It doesn’t even have to be registered but perhaps it’s a good idea to do it. A notary isn’t needed. Here’s a link from the ZKB with info on it (in German but can be deepld):
https://www.zkb.ch/de/private/vorsor…geauftrag.html
It’s not much help with the will but for poa it seems to be much more straight forward. I haven’t gone through the process myself so not sure what is involved in terms of documents e.g birth, marriage certs etc and again it might differ in each canton.