Replacement mortise latch for patio door CD8B

Hi there, my lock is similar to one you have posted on your site but it has larger mounts on the outside with what looks like a patio door symbol on both ends.

It is stamped CD8B inside, and measures 5/8 across the part that inserts into the door (width) and 3 3/4 roughly from each center of the mounting screws. Total length is 5 1/4.

I have included pictures and the measuring tape in the photos. Please help me find a replacement - I cannot find the manufacturer on the doors anywhere.

Thank you, I'm a little leery of the screw placement and the amount of space between the drilled hole and the top of the surrounding bracket (mine is definitely longer with the little symbols of the patio doors on it). I will have to look at the keeper to see if that will fit. I don't mind if it's not exact, so long as it is secure and locks :).

If I order this and it doesn't fit, is it returnable?