A few points....
I'm presuming you are operating as a sole proprietorship, go to a book store and pick up a guide to starting a small business it should have all the info you need for basic record keeping.
VAT on goods from the UK, inform your suppliers that they do not need to charge VAT if the goods are shipped outside of the UK, they do need to have proof of export (VAT works almost exactly the same as our GST). It may be possible to apply to the UK for a refund of VAT charged (check with "Inland Revenue" in the UK).
Duty on antiques, don't know the current rules but years ago antiques older than 75 years were duty free (but nothing is GST exempt). I just checked the customs tariff, antiques must be 100+ years old to be duty free.
Ben

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
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