If it is a standard model B I'd think so. If it is a B-SE the forend might be different. The B-SE had ejectors instead of extractors and there might be enough difference to matter. Might not. I've had both the 311 and a B-SE in the past, but it has been years so I'm hesitant to say for sure.
The old 311's are everywhere, I call them the workingman's double. Many minor variations over the years.
I remember lusting for a Fox model B as a teenager i had one of those big guns annual edition softcover books, I just fell in love with the Fox model B.
Years later I finally put my hands on a Fox model B and I learned that I had not fallen in love with the Fox model B.
I had fallen in love with a picture and the breathless advertising copy of a Fox model B.
The Fox model B MAY have been why the term Lipstick on a pig was coined.
It's a gussied up 311, and not well gussied up either. It's not a bad gun, that said it really has no business wearing the Fox name.