In light of this discussion: Local shop had a PT145 and some Para (brand, I think) P14 mags on the rack. They let me try them for fit; obviously not for firing function. The base plate of the Para mag has a locking tab that extends out the rear, and prevents the mag from seating all the way in the mag well of the PT145. If, however, you removed the tab or just slid the base plate forward (like I did), the magazine seats fine and functions to lock the slide back. As shown in the pics above, the follower looks the same, and the only difference appears to be the shape of the cutout on the back face of the magazine body.
FWIW.
Don