Also on
https://bithd.com there is no social media links or links to bitpie, while bitpie has broken links to Play Store and the relation of the two ... well, it gets explained in a
medium post.
The official site has no social media links. At the end of the Medium article you shared, you can find links to Bitpie's Facebook and Twitter pages. The only Telegram channel that still seems active is the Bitpie Wallet News group.
I can't find the Razor on sale neither. At least not in English. And hardware wallets should probably always be bought from the manufacturer anyway but they never sold it on their website, right?
I remember that they always linked to Amazon and Ebay since their ANN thread was created. You can check it out
here. And yeah, there doesn't seem to be any devices on sale on those two platforms now. If you click on the buy button on their official website, nothing is available.
Regarding the verification of the source code, have you looked at this tutorial they posted?
https://bitcointalk.org/index.php?topic=5235828.0