Morning George,
Does it say HILSON (and possibly/probably Bolero) on the pipe?
Hilson was the first company to introduce this style of pipe (1960s I believe) and there were knockoffs but most were well made and passed for the Bolero without closer inspection. Hilson made some well respected mid-range pipes.
High draught hole won't gurgle by itself but it prevents burning all of the tobacco. I wrote somewhere else that most gurgle is caused by a partial obstruction of the draught hole with a wet piece of tobacco that flaps on and off the hole.
Tapered bowls are intentional (some manufacturers) and the merschaum insert was obviously made this way. Different schools of thought on whether this is a beneficial or not. If the hole is too high, so that it interferes with a good smoke, you could try some pipe mud to raise the bottom but if it smokes well, I'd not bother.
So, how does it smoke?
Pete
2015 Blood Meridian in a 1970s Caminetto Business #104 saddle billiard. Last of this mixture (not quite a whole bowl). Dr. Brown's diet Black Cherry on ice.