It was "suggested" AHR is no longer working CZ Upgrades, inflation, lack of demand & CZ discontinuing their 550 doesn't really leave fairly inexpensive options .. I may sadly be mistaken.
There's a member here I look forward to talking 'c as he's a wealth of information on this topic.
However, there's a fairly basic used Smithson (if there is such a thing) for sale @ an overwhelming price. A new CZ 505 for $10K, etc. (I see more Big Bolts "Sale Pending/Sold" certainly more than a few years ago)
If this leaves exclusive builders who build 10 per year, I couldn't imagine the proverbial cost & eta.
Again, I may be mistaken, but
@W.J.JEFFERY & CO. (if you can get one) may quite the investment! ;