Masons C1850s Floral And Birds Ironstone Plate 9"

I have found this beautiful plate at estate sale previous owners passed away i  purchase a couple of pieces this one was amongst one of them it's absolutely beautiful but it does have some signs of where I'm not sure if it was used dinner  table or if it was just on display but it does have a yellowish mark on one side where you see my finger pointing it's not broken it's not damaged it's just very old so please if you are looking for a vintage probably an antique piece this is one of them but make sure to zoom in on all  photos sale as is Sale as is please keep in mind this is a vintage or maybe an antique plate do your research before your purchase this is what I found online regarding the markings in the back of the play it does have a tiny little line of yellowish Mark that it looks like it's from age or staying I'm not sure if it can be removed but I do not want to miss up the art so I'm leaving it the way it is