Reproduction plates are available, since you have the number buy a plate and a set of stamps and recreate what you truly own. Here is what an original 50' plate looks like as a guide. I think frame stamps would be a bad idea as these trucks are not stamped on the frame. For 1950 the screws shown are also correct they replaced the earlier clutch head versions shown here.
http://www.flickr.com/photos/advance-design_parts_co/8129122101/in/set-72157631867396207
http://www.flickr.com/photos/advance-design_parts_co/8130544334/in/set-72157631870734114