I wouldn’t get too hung up on the salary at this point. It’s not a million miles from your current salary.
Concentrate on the interview, making a good impression and asking about prospects, overtime, bonuses schemes etc. If they ask what salary you are on just say that you are currently near...
How does the role, prospects and package being offered compare to what you are on now? What do you think you are worth and how does this compare?
Not really sure why you are asking and I may have missed the point?