You can't beat those Lufkin Tools.  They built nice tools back in time. I have a set of them that measure from 0 to 7".  In my small shop I hardly measure anything over 3" diameter.

Welcome to the forum.  Nice collection of mics you have there.   
For some unknown reason I never aquired anything larger than 0-1" mics and end up using calipers most of the time. 

Came across this pair on the ebay and couldnt pass em up.

Part of the reason I asked about sources.
I found this listing on eBay: https://www.ebay.com/itm/256770677339?_skw=aloris+bxa+tool+post&itmmeta=01KNPXF9XBBT1H9PHD9DW23JA3&hash=item3bc8b99a5b:g:brcAAOSwBahVAIhi&itmprp=enc%3AAQALAAAA0GfYFPkwiKCW4ZNSs2u11xC1G--9Iyq76QCGVvpL6dnqtOmYBt9HQUL3pv5kHUpMhnRW86ZiY5vo0%2F7VuDmbP%2FeNzcQVMYcRIkUWzQUXUwGrzUEtcwjYtDopXicOQSZQlY%2FPM1%2FB3qtiakJ0xxp9Pjnje3qcorCGAAHRFFLC5W1KPav%2F6sIdz9bCDYDEyZBmoEdvw4fZUe5mii2VZAvvsJ6cIJ747pC3jDXtWYh0zCH371qtLmBqlXhK9lFS00b9kQE6YKrgbZNkw%2BxizdkiHls%3D%7Ctkp%3ABk9SR4yfvd2tZw

Prices are all over the place whether new or used.
I'm also wondering if the new tool posts from Aloris and/or Dorian are as good as the old ones.
If they've outsourced manufacturing or moved manufacturing facilities outside the country, I don't see paying top dollar for them.

Have you checked the price for a new BXA tool post from Aloris by chance? There's no sitting down, immediate heart attack!!! Almost $1K now, not including any holders!

Most used Aloris and Dorian tool posts out there for sale are worn. They may hold accuracy and may not. I would suggest buying a Shars brand QCTP. Yeah, they are Chinese for now. Trend now is this stuff is starting to show up coming from India. Just as good quality if not a tad better.  Sad thing is, the steel used to make the goods comes from China.

Hmmmm.   

Ebay comes to mind, naturally. It might be worth checking Craigslist and Facebook Marketplace. I have been rather amazed at what things you can find in those two places.

For new I guess all you can do is search around.

For tool holders I've had very good luck with Shars. Not American made, but they have been just fine. I can understand being a little more discriminating about the QCTP tool post though.

Good luck in your search!

I've been shopping around for a QCTP for my Logan 6560H.
I don't want Chineseium so looking for either an Aloris or Dorian in a BXA size. Will need tool holders as well.
Any recommendations for sources of new or used ?

I made this die filer many moons ago. I don't use it much, but when I do, it's irreplaceable when doing a specific micro machining job in my Hobby Shop. Pic shows it mounted on my Levin lathe. And not just a Levin. It could be adapted to many other Watchmaker Lathes.
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That container just sits there with cutting oil in it. My lathe is set-up for coolant. But, I do not want the maintenance that goes with it. So, that little container is all I have to help in machining. For me, it's good enough. And I try and stay away from machining stainless! The container is shop made and I did not make it. Can't remember how I found it, it was too long ago.