Yellow metal case with SS back. Back of case marked, "Bulova" with the date code. Then "10K R.G.P. Bezel", "Stainless Steel Back" and the serial number across. Inside of case marked, "Bulova", "Fifth Ave", "New York". Yellow Metal Band Caps with ss back. Marked with "Speidel"on back link (in two directions) only. It is "OK". Probably will replace with leather if I cannot find the correct band. Last serviced in 2010 with synthetic oil. Runs great. I wear occasionally.
Appears to be a 1959 Senator "B"