Beat me to it mate. My first visit to Bloomfield was to watch England v N Ireland schoolboys - school organised a trip to it. Then saw our reserves play Liverpool's in about 1973-4.
The Watford game was the first 1st team, Graham Taylor's team that went through the divisions so I guess it had the likes of Luther Blissett and Ross Jacket up front? Memory is that we played really well and deserved more than the 1-1 draw, Stan McEwan scored at the South end.
Like you, I can remember the bloke in the row in front!