Well I received an aluminum main spring seat (short) measured and compared to a new Sig plastic part, and the "Matrix precision parts" seat was an exact copy, fits frame (P228) tight as factory part, zero wobble, dimensions all perfect, the springs locating surface when installed is same as factory height. Very well made excellent quality. But the slot at bottom for assembly tool has radius sides instead of squared off like plastic one which will be stronger and easier to manufacture.

You should REALLY update your original thread....It's not that far down the list

https://sigforum.com/eve/forums...0601935/m/8780005044