After months of waiting for them, I finally got my two barrels last week. Yesterday I was able to get back to work on this project. Here are a few photos of what I've done in these two days:

Here they are, a pair of McGowan, 26" barrels, in the Shilen #2 profile. Rate of twist is 1:12.

Here I'm turning the shank end to the OD of the front end of my monoblock.

Threading the barrel shank, in this case, 13/16"-32tpi.

Reaming one of the chambers. I read elsewhere of a formula for lubricant for this job, consisting of 50% Ford type F automatic transmission fluid, and 50 % SAE 10 motor oil. This is the first time that I've used it and it's great. After cutting both of these chambers, with only a finishing reamer, I slit my finger open on one of the flutes while wiping the reamer clean. That's still SHARP.

Here we are with the first barrel screwed up tight into the monoblock.

And here's the second.

Here are two dummy cartridges in the chambers. Barrels lock up with lever still well to left of centre, but things will wear in as we go along.

More to follow, with better photos from a better camera.