It's been overfed 'something' .. but that doesn't mean all things have been overfed. Dial back overall concentration, but if you see new symptoms progress you may need to make further adjustments.
i'd wager the spots that resemble Ca-deficiency is really Ca being locked out by other nutes. weighted average of Ca% should be about half of what K% is. this is a very non-precise ratio, but anything in the ballpark is probably fine and could help chose between Ca deficiency along with some overfeeding of other stuff or Ca being locked out if enough is avialble and still getting the rust spots.
The leaves look dark and abit shiny. Probably too high in N. Other things possible too.