Tinker:
There they are! Thanks.
These same photos were much smaller in the link, and I didn't notice what you referred to here:
The long-length of the old barrels up the undersides of the 'new' barrels looks to be a way the guy who'd done this could run his original forend wood. Also it extends the area of the solder joint -- I wonder what they used to join these.
You're certainly right - of course with the much smaller diameter rifle barrels sleeved in (again notice the big "step"), the fore-end wouldn't fit, and that's certainly the function of it. But is what we're looking at a remnant of the old barrels, or did the smith make a "fillet" that is brazed or soft soldered onto the barrels much like the "shoe" on a set of shoe-lump barrels? Impossible to tell from the photos. Looks like the guy knew a little. The seam between the old outer tube and the new inner tube is unmistakable in the third photo.
The conversion wasn't done in the UK. The lack of re-proof would have been illegal there, and unheard of here.
Gaugedrifles, please let us know what you hear from the proof house. I'm quite conversant with British proof, and I can't imagine what mark, or remnant thereof, that mark could be. May I suggest that you also include all three photos, and ask them what they think? Make sure the size is like that above. I'd like to hear what they say, as it's a very interesting set of barrels.
BTW - I didn't mean to be laconic above. I regret that it wasn't the news that you probably wanted to hear.
