Thank you for reaching out to others for help. In regards to this, no there is nothing else marked on the receiver under the wood line. The only other thing on the barrel is a "44" marked about half way down the barrel under the wood line. Other than that "44" there are no other markings or numbers.
---------- Post added at 07:01 AM ---------- Previous post was at 06:54 AM ----------
I should have included a better picture here but in person it is definitely a "Q". It is also marked on the stock. I do agree that the serial number looks untidy but I would argue it is the placement of the "T" that throws it off. I could see where this could have been Q 1728 but my issue here is the space between the Q and the 1728. On all the other Carcanos and Vetterlis I own there is not as pronounced a space between the letter prefix and the serial number.
Now that I think about the possibility of it originally being Q 1728 that doesn't match up either as that Serial would fall into 1942 production and it is clearly marked "FAT 41".