I work for MCM. We're closing down, if you didn't hear the news yet. Showroom is closing at the end of September. Don't know how much longer orders will be taken or whatnot. Rest of the company will be closed down by the end of December, is what we were told. Shame, but that's life sometimes.
I used to use them a lot, mainly for Asian transistor types. I have to say as Mouser and Digikey now stock many current Asian types, I have had less reason to go there in recent years. I suspect my experience is not unique.
I also used to buy things like rubber belts and idler tires as used in tape decks, cassettes, VCRs, etc. But the repair of those things has all but vanished, so again, another thing they won't be selling me.
Shop supplies like solder, flux, chiller, contact cleaner, heat grease, etc are available anywhere.
I liked the company, but their core focus didn't seem to change with the times.