Case back:BULOVA N2 STAINLESS STEEL and the serial number.There is a definate space between the first two numbers.73 movement in a 72 case? Inside case back:Initials(stylized) RV maybe,7265-2 in a rectangle,SWISS. Movement:23 jewel 11AOACB dated N3. Dial:Very nice mettalic blue ,day date and reads BULOVA,AUTOMATIC. I don't know if the band is original;it has no markings other than STAINLESS STEEL
I've gone through our limited number of 70s ads and did not find a match to your watch. I'm wondering if it was a model sold/manufactured overseas internationally, since we typically see a '23' marked on the dial for US models with a 23-jewel movement. Also, not uncommon to see a one-year difference between the case and movement. I think also that the band is not original; only because I don't feel Bulova would have used the type with the adjustable ends.
Looks to be an Unknown model, at this time.