Help identifying antique Rolls Royce grill

Hi! My grandfather restored antique cars for a living and was quite amazing at it. He recently gave me an antique Rolls Royce grill to sell, but he is losing his memory and can't remember when he got it. We're trying to find out anything we can about this grill, so we have an idea what model it is, what year, etc. Any help would be greatly appreciated! I have pictures and measurements. It is 22" from side to side, and 15 1/4" bottom to top on the sides. It is missing the ornament on the top of the grill, but other than that is is in gorgeous conichttp://i256.photobucket.com/albums/hh197/jeanniest/florida009.jpg http://www.automotiveforums.com/vbulletin/%5BIMG%5Dhttp://i256.photobucket.com/albums/hh197/jeanniest/florida009.jpg%5B/IMG%5D