No they are not
To expand:
There's literally hundreds of instagram pages that have popped up scamming people. They are usually named something similar to what you have said "datsun_source_parts" or "Datsun_spare_parts" etc. They'll entice you in with low prices and will offer shipping (free). They won't take PayPal and will instead ask for Zelle or another app that won't allow you to reclaim your money. The pictures are usually stolen from the internet. You can try and ask them to show you a photo with some paper with their name on it, but that's easy to photoshop these days
It's worth mentioning that there's also lots of these scammers on Facebook - the best way to look out for them is their profile will be very bare. Likely it will be made a few days prior (so cover photo + profile picture both updated a few days ago) and they'll use the same method as above to try and get you to send them money. Some Facebook profiles have been hacked, so you might see them with 300 friends all from South Africa, and suddenly they're trying to sell Datsun parts in the UK. They also seem to have very generic names like Jack Smith.
I would be very hesitant at buying anything online from anywhere other than these forums or an established shop. If you do buy something, never send it via Bank Transfer, Western Union, Zella or CashApp etc. If you do use PayPal, make sure you pay for Goods & Services. If possible, link a credit card to your PayPal and pay via that.
