Best way to join 45 degree window screen stock corners?

[M>B>]

I made 18 wooden screens for my 100 year old clubhouse and I used a butt joint, dowels and a screw, with weather proof glue. Routed out a grove on the mahogany I used and installed the screen with a spline, just like aluminium screens. They were painted with opaque stain and 30 years later they are just as new±.

I might add that an improvement like this will never pay itself off with the sale of the house. Best return during an inspection is to bake some cookies or brew some herbal tea!