I bought this 20 years or so ago and I just put it away at that time. I don't know if this was some modern creation or an ancient coin weight (exagium), it just came as part of a big lot and I really hadn't given it much thought. It does show a "phi" and monogram in an incuse punch on one side and is blank on the other. Does look like some honest patina but who knows. Just curious if anyone has seen something similar to this before. The piece is 35mm x 20mm and weighs 27.1gms.
I dug through some old boxes and found the other one that was part of the old lot. This one has two central figures facing with some Greek text to left. It's 25 x 28mm and weighs 37.4gms. If they're modern (and they may be) someone went through a whole lot of effort to create this one. Also, they are probably some sort of lead alloy by their weights.