VAT on imported used motorcycle parts from EU

Downthedrain

Are any additional charges due on low-value secondhand parts posted to the UK from European dealers who are not VAT registered either in their home country or the UK? My understanding is that any seller to the UK has to be HMRC registered for sales under £135, and VAT is charged at the point of sale. Effectively, the seller acts as a UK VAT collector. If the seller isn't registered, then no VAT can be charged - so what is the situation? Is there a risk of parts attracting VAT plus a hefty collection surcharge before being released to the buyer? The other issue is that VAT on used parts is often at a differential rate, applied to the difference between what the dealer paid and what they sold for. Only the dealer would know this and any UK assessment on the gross cost of the parts would be inaccurate.

Would someone clarify this for me? I've looked at the HMRC notes and are no closer to understanding this.