The creator sells boards with either matias or vintage alps. There's a limited supply of the vintage ones though. You can also buy a kit and provide your own switches of IIRC when I emailed him he said you can also send him the switches if you wanted a variant of the Alps that he doesn't have.

I've tried modern and vintage and even modern ones modded to feel like vintage in various boards and the real vintage ones are far superior.

I love my keyboard with Matias quiet click switches but they absolutely did have a bad batch that die super quickly. Had to buy a bag of spares to swap a few switches out.

These appear to not be Matias though based on the stems https://deskthority.net/wiki/Matias_switch