David;
I would totally agree with Raimey as to the likely meaning of the 672. both bbls seem to have 17.0mm bores which converts to .669". I cannot read the upper numbers real clear with my old eyes but appear to be 16.4 for the left bbl & 16.6 for the right one. This would thus represent .6 & .4 mm constriction respectfully or in English .024" left & .016" right. for a 16ga I'd call that a modified & an improved modified or in European terminology ½ & 3/4 chokes.

Don't really recall now what you said about condition, but if in any condition at all I would think this would make a great shooter & certainly be worth that. What else could you buy these days for that amount of money??

Miller/TN
I Didn't Say Everything I Said, Yogi Berra