EuroArms was kind of an assembly house. Sometimes they just put their stamp on guns made by other companies, sometimes they assembled guns made from parts made by other companies. Brescia is a town in a very old gunmaking region in northern Italy. Several companies have been located there. I have an old EuroArms percussion Remington 1858 New Model Army that I bought sometime back in the 1970s. Here is a photo of the EuroArms legend on the top of the barrel.
This one was actually made by Armi San Paolo, an Italian arms maker that is no longer in business. This is a photo of the Armi San Paolo logo, on the under side of the barrel of my old Remmie. D,G,G inside a circle. See if you can find any maker's logos anywhere on your '73. I am not aware of any other companies making replicas of the '73, but there may have been.
I will second Happy Trails, he is a wizard with old guns, he can often fabricate new parts, or add some weld to build up a part and reshape it.