Well it isn't a current model as it isn't on Rotary's website but many online merchants still stock it so it 's not that old. However, your picture would certainly suggest that it's older than 18 months or so, one wouldn't expect that degree of marking in such a short space of time. Also, who chewed the screws, no competent jeweller should have done that. As to the timekeeping, it's a quartz so should keep pretty well perfect time, I'd go back to wherever it was bought but since you've had someone else open it they might be a little disinclined to assist.