Steve, you can find left hand carbide insert boring bars from a variety of sellers; I've an insert holder of similar hand and style.
Here's an ebay link from a UK supplier as an example.
I've not used that supplier, or these bars personally, but am in the market for something similar.
If you decide to try one, I'm sure we'd all appreciate a review.
Also on ebay The Tool Shack has some ½" brazed ones available at the moment
Bill
Edited By peak4 on 27/11/2020 14:31:50