I cannot speak to VAT but I have had some recent experience with importing from the US into Canada. Here we have the GST (7%).
I brought a Blade in from Florida by truck. When it arrived it was placed into bond and I had to bail it out by paying my 7% taxes before it would be released to me. A bit costly but relatively easy.
Now due to some flamboozle or other the mainsail had to come from California via UPS. It was shipped via "Warranty repair and return" because I had already paid the taxes when I paid for the boat. Therefore, I had no duty or taxes owing on the sail when it arrived. BUT, the good people at UPS felt it necessary to charge me over $60 to broker the customs paperwork. They wouldn't allow me to self-broker.

So, you will probably receive your blocks with a COD attached for the value of the VAT plus potentially a substantial brokerage fee. You may need to research the shipping options available to you to see if you can minimize or eliminate this onerous fee.
I was informed by UPS that to self-broker, I had to be at the port of entry. When I explained that I managed to do the boat at its destination, not the port of entry, they replied "We don't work that way". When I suggested that I shouldn't be using UPS, they replied that if the sail had been air-shipped to Edmonton, then I may have been able to avoid the brokerage fee. Of course, I probably would have given the airline more than that in increased shipping costs.