I just received the Trimark unit. It is a almost perfect fit. To make it a perfect fit I had to grind the right side of the outside box for about 0,5 cm and had to round up the corners. I used a hand grinder for the rough part and a table grinder for the finish. As for the final result I have used rotative sander with 280 sand paper. The resilt os a clean cut and it looks great. Just added some tremglad black paint
with a small brush and you dont see the difference.
I had to cut ou a little bit of FG on the door to get the unit in place. Just in the corners of the fitting box. The pen lock fit perficly.
The door now locks great and as a thighter fit . The guide screw just fit perfect in the original female unit.
So as i am concern, this is a great upgrade and find it more relyable than the old L-300.
Here are some pics and if have any question...
Again sorry if my english writting is not perfect!