1954 movement in a '57 (L7) case. Nice stainless case and back. I have a feeling the stem on the watch is wrong since it protrudes so far from the case, or the crown is wrong. I don't know. The watch is hard to set turning it forward, it tends to make the crown come undone. It sometimes runs for awhile but not always. The movement needs to be serviced. I was planning on installing a nice working black faced movement into this case as its currently in a non Bulova case. I can't figure out how to remove the crown to remove it from the case however.
I'd say Bulova 23, very likely a swap at some point in the watch's history, but at least it is all '23'.
I strongly recommend (as always) getting the watch fully serviced by a qualified watchmaker. Dirty or dried out watches can and do damage themselves by running, and you cannot oil a dirty watch. It must be completely disassembled and done properly. The crown or the case tube is incorrect, and should be replaced with the correct one. It is too easy to snag a protruding crown, and having the stem ripped out can cause some serious damage.