Hello. Up until a few weeks ago, you could've gotten brand new Mec-Gar 13rnd HP magazines from New Heveltia, but last time I checked, they were out. ($25 ea.)
Right now, you can get Mec-Gar magazines (13rnd) from Wayne Novak, the gunsmith. Cost, etc can be found at http://www.novaksights.com
You might also check at http://www.cdnninvestments.com as they've had Mec-Gars in the past and I THINK are still selling Inglis magazines. These are Canadian-made HP magazines that I've had good luck with in the past. You might also consider the SA 17rnd magazines if they still have them. I've had good luck with several I bought.
If neither of the above suit you, try ProMag's 13rnd HP magazine. Finish is not as good as the Mec-Gar and I don't think the steel's as hard, but these can usually be had for around $15 a pop. I've tried several and they worked.
