Question about M203 Sight mounts ...
 

I was wondering if this appears to be a standard M203 sight mount?

http://i51.tinypic.com/4id9gk.jpg

And if so, is there any way to attach a M1913 accessory rail on it with a commercially avalible product?

I'd rather not machine my own mount or modify a existing mount, but if I must I will.

Thanks in advance.

Dimitri