Anyone ever seen this type of mechanism in a pipe before?

[smbauerllc]

So, 3 questions:

1)Anyone ever seen this type of, I'm assuming built in filter, which reading and seeing pictures of those eras print ads, seemed to be the hot ticket, on drugstore pipes at least, in the 50's and 60's?

Not all the estate pipes from the same estate auction have built in filters, but 3 of the 6 do, and possibly 4, but one cannot be disassembled, so I'm taking a guess that it has one too, which is why the stem can't be removed, and that all 6 are drugstore pipes from the 50's or 60's based on the built in filters, inability to be disassembled, and 50% of one bowl having been taken up by cake in one, which has to take near forever, even without ever cleaning, to get that much. This was clearly the deceased gentleman's favorite pipe.

The vents are on the top and bottom of the stem right at the shank, and draw in a lot of outside air. Just curious if anyone has used one like this, and how the smoke production is with so much outside air coming in. I'm sure it makes for some very cool smoke, assuming you get any.

I know I could just pack a bowl and try it, which I plan to do today, just curious as it's an odd device and hoping someone has some experience or information about it.

Slots in top and bottom of stem where it meets the shank.

"Filter" permanently fixed inside shank. It does also have a hole in the end

2) Anyone able to identify this makers mark seen in the first picture above?
Pic isn't the greatest due to my Essential Tremors, but it's a "broken", 3 sided square surrounding the letter "C". No other markings on it anywhere

3)Anyone able to decipher a makers name starting with a "V" and ending in "llo" with approximately 3 letters in between?

I know it's not much to go on, but the stamping is faded in the middle, i have poor eyesight even with glasses due to cataracts, and there's a nick directly over the second letter and its worn in the middleof the name. Below the name it says "Imported Briar".

Tried to take a zoomed in pic, but between not being able to hold the tablet steady and the wear, it just wasn't at all visible.

Thanks guys. Someone has always come trough for me, or at least tried their damndest, and as a complete newbie, all your help has been greatly appreciated, especially with the more dumb newbie questions.

Thanks again for any info you can give,
Sean