The fluted cylinder looks a lot like the one made by Classicballistix who was posting here when he 1st started out.
His website has a link to the Old Army Club and says that he will provide a discount to THR ROA club members.
But his initial price is much higher than the eBay vendor.
Nonetheless, see page 2 post #28 of the Ruger Old Army Club to see the 2 cylinders that he made for AbitNutz, and you can do an advanced black powder forum search to
read some of AbitNutz posts about how well his worked.--->>>
https://www.thehighroad.org/index.php?threads/the-ruger-old-army-club.538088/page-2
I would be surprised if you found someone to reply who bought a cylinder off of Ebay.
That seller has only sold 21 of them off of eBay.
It occurred to me that they might be from the same maker, but Classicballistix lists his location as Texas, whereas the eBay vendor lists that he is in Georgia.
Here's the Classicballistix website. --->>>
http://www.classicballistx.com/our_cylinder.html
The THR discount is mentioned on the page that it takes you to if you click on the button to buy one.
The page states: "We offer a DISCOUNT to members of the High Road's
Ruger Old Army Club and to S.A.S.S. members.
Please request an invoice to receive your discount"
He has multiple cylinder options to choose from.
His ROA cylinders were noted for having slightly increased cylinder capacity for loading additional powder.
Which other websites sell the cylinder from Georgia?
Can you provide links?
Some of the eBay feedback for the Georgia cylinder mention having a good fit, but that's about all they indicate.