[Jim McDougall]

While awaiting hopefully replies from others with specific knowledge on this field, I thought I would respond as well with some thoughts.

It is important to note that the term 'dungeon' is of course referring to the word 'dudgeon', the type of wood often used on these early dirk hilts usually of 16th and 17th century. These developed from the 'ballock' daggers which usually were haunched, leading to this rathy baudy anatomical association (in Victorian times the term was revised to 'kidney' dagger to relieve the tensions of prudish Victorians by reference to the lobed organ). It is known that the term 'dudgeon' was extant far earlier as it is mentioned in cutlers ordinances of 1379-80 referring to the use of 'digeon' or boxwood, which was typically pale in color and often dyed. The use of the wood is further mentioned in "Gerards Herbal" (1597). The word dudgeon has become connotated with anger, resentment and probably linked to the use of these daggers in such instances as may be expected.

The hilt is of course variant from most ballock or early Scottish dirks though it does have a cuff or collar at the base of the hilt, but no evidence of haunches or lobes. It would appear that the incised openings were for the placement of insets, much as the type of decorative motif on Scottish dirks and knives which were of course quite personally embellished often.
The placement of the mark is consistant with the quadrant of the blade typically seen on European knives and cutlery, and while it has the character of many marks with spurred and accented geometric images, none are directly corresponding (I checked "Knives and Scabbards" , 1987, Cowgill, DeNeergaard and Griffiths, and Wallace Collection, Mann, 1962, "Scottish Swords and Dirks" John Wallace, 1970).
Makers marks were however seldom exactly reproduced as the stamp became worn and the images degenerated, as well as of course others trying to copy them. In the first reference there are only two marks of 119 which might be from the same stamp.

While I cannot say for sure what the exact character of this knife or dirk might be, it does appear to be within the range of these early daggers and earlier dirks, quite possibly Scottish and likely border regions. The best hope for the mark is looking for a close match in the configuration in catalogs and other references.