Tripod identification needed

Anyone know what this tripod is for and any info about it and what weapon it was used for?
Thanks Rob
https://www.milsurps.com/images/impo...3/4vjuwl-1.jpg

Difficult to id properly. Some side shots & close ups of the mounting points & eleveation mech would be usefull...........

Here is another picture not very good Ill have to take more
https://www.milsurps.com/images/impo...3/awx6ok-1.jpg

Looks like there's something in the .30 cal range there, not heavy enough to be .50 cal range. (Ma' Duece) is a big machine gun, therefore requiring a bit more beef in the tripod dept. I can't tell by looking exactly either, but does it have any (U.S. markings or quatrant nubers or anything, to identify it as U.S.) There are several typs of Small arms that could fit on a tripod like that. Just not sure, sorry.

Its a FN D tripod, but it has a extra leg attached to the front of the front leg that I don't recognise, could be a AA leg?

http://i305.photobucket.com/albums/n...D/IMG_0351.jpg

There you go! Seek & ye shall find! Well done BP! ;)

Thank you very much