"It was cleaned before being sent to me." In my heart I accused my companion of putting forward a most lame and impotent excuse to cover his failure.

What data could he expect from an uncleaned watch?
"Though unsatisfactory, my research has not been entirely barren," he observed, staring up at the ceiling with dreamy, lack-lustre eyes.
"Subject to your correction, I should judge that the watch belonged to your elder brother, who inherited it from your father." "That you gather, no doubt, from the H.W.upon the back ?" "Quite so.

The W.suggests your own name.

The date of the watch is nearly fifty years back, and the initials are as old as the watch: so it was made for the last generation.

Jewelry usually descends to the eldest son, and he is most likely to have the same name as the father.
Your father has, if I remember right, been dead many years.