I have some Matias blank keys for me to replace the modifiers. I am using the Matias Quiet Pro, meant for a PC, on a Mac. I changed the Windows key to Option and the Alt key to Command key and so needed the blanks modifiers to hide them from my view so I can press them correctly. Through this purchase, I found out that Matias keyboards have undergone some changes in the past 10 years where all the modifiers are now 1.25x. In the older design, the Opt/Windows key is a 1x. Cost me a bomb to buy from Matias due to shipping. And, it seems, no one is selling Matias keyboards used (not here, DT nor Reddit).
Happy New Year, GH!