I recently bought a Mexican 1968 25 pesos from a dealer at a flea market. The coin has a reeded edge and the strike is a little bit weak, and is also magnetic. On my Krause books it only lists the coin without a reeded edge. Is the coin a Chinese fake?
We need more info than that. Weight, pictures.. Maybe your looking at wrong info in the book? I have seen Chinese fakes in flea markets but I can't give a definite answer without better info.
They are very commonly sold fakes at flea markets. I have seen the exact coin you are describing OP at flea markets here along with the usual fake crap like Trade dollars, "1805" silver dollars, etc.
Those and other crowns like it are very common out there. Use a magnet next time. Also, take a good look at it so you know what crude fakes look like. I can spot them easily now--they tend to have mushy details, weak strikes, and wrong alignment when flipped. Edge discrepancies are harder to discern unless you have a good memory. There are also non-magnetic fakes but that's another story.