Well it's really about UK tax. So far only one out of three questions I have asked could be answered.. please cancel the question
Sure, let's try that.
They are almost all overseas companies and no tax was deducted at source.
I also have some dividends from a few UK companies which was subject to a 20% withholding tax (this tax paid I offset against my Austrian taxes).
24 years ...
I opened the brokerage account a couple of years ago. Other than that I have no other UK sources of income and no ties to the UK apart from citizenship. I visit relatives about 2 weeks a year typically.
Many thanks for the comprehensive response and links