The brand I-N-C has a few men’s button downs with black flocked velvet, and it looks like they ship through Amazon. Excuse the shitty long links below, I’m on mobile.

Geometric pattern:

https://www.amazon.com/I-N-C-Flocked-Pattern-Button-Shirt/dp/B07WJCRQD2/ref=mp_s_a_1_11?dchild=1&keywords=I-N-C&qid=1625811622&refinements=p_n_size_browse-vebin%3A2343349011&rnid=2343347011&s=apparel&sr=1-11

Different geometric pattern:

https://www.amazon.com/I-N-C-Flocked-Button-Shirt-Black/dp/B07VHG9MT9/ref=mp_s_a_1_17?dchild=1&keywords=I-N-C&qid=1625811682&refinements=p_n_size_browse-vebin%3A2343349011&rnid=2343347011&s=apparel&sr=1-17

Similar pattern to reference, but it’s navy:

https://www.amazon.com/I-N-C-International-Concepts-Paisley-Collared/dp/B0948BSR4G/ref=mp_s_a_1_1?dchild=1&keywords=I-N-C&qid=1625811754&refinements=p_n_size_browse-vebin%3A2343350011&rnid=2343347011&s=apparel&sr=1-1

Tbh it’s probably worth poking around Amazon some more to see what you can scrounge up. I’m not even having any luck finding what you’re looking for on Poshmark/Depop/EBay, so Amazon is probably your best bet.

Edit: looks like Punk Rave has a couple of men’s button downs as well? The Nocturn shirt might be close to what you’re looking for. And they also ship through Amazon.