To remove the crystal, you need a special tool called a crystal lift. It squeezes the crystal around the edges to reduce the size ever so slightly so it will come out of the case. It's not for the light of heart and best performed by a jeweler who repairs watches.
Some Bulovas are hard to narrow down to a specific variant due to the way they were advertised. An example would be a watch in yellow gold advertised as "G" variant but; listed as also available in white gold - a variation. White gold could be the less popular style and an "H". but never advertised as a "stand alone" model. This one likely falls into the same catagory. Some watches were assigned a different variant letter based only on the band (leather or metal). Think inventory control. It's a slippery slope without some way to verify with ads or price lists from Bulova from the time period.