What is the exact size of this ground glass?

I need to replace the ground glass in my Burke & James Orbitar SW.

I measured the glass in it and it is 13 cm by 10.5 cm. I have found this glass at B&H

https://www.bhphotovideo.com/c/prod..._180_801_4x5_Groundglass_Focusing_Screen.html

Which looks as if it should fit, but it is for a toyo. Does anyone here know its precise measurements? I asked B&H and am still waiting for them to find a ruler somewhere .... I figured the geeks here have rulers laying around all over. I want ground glass with the grid.

And if anyone has one around of the proper size and grid, and is willing to part with it, I'm happy to pay any fair price.

Can anyone remember the name of some guy I saw here a year or so ago who made/sold glass for cameras and enlargers?

Thanks

Charlie

Maybe Steve Hopf can help. I got some glass for my enlarger and my 5 x 7 from him last year.

Dead Link Removed

There is this one, but you'd need to draw a grid;
http://www.surplusshed.com/pages/item/l1034.html