Screw in tub overflow plate

I got a 1950's tub with a screw in overflow plate instead of using bolts. I have never seen one of these and unable to find one anywhere to replace it. Anyone run into this and got any suggestions?

Problem solved

Well, decided to get the plumber in on this one and he went up under the house and replaced both tub drain waste in 2hrs for $375. Wasn't too excited about having to do that at first but then he said one tub drain had been leaking so good thing I did change them. So bye bye to the old one and now I am a happy camper. Now if I can just find those pesky valve stem and trim replacements I will be set.