This ad says "1951-54 Henry J bumper gaurds" it also says they fit Darrin.
http://cgi.ebay.com/ebaymotors/1951-54-Kaiser-Henry-J-Darrin-bumper-guards-/150635653591?pt=Vintage_Car_Truck_Parts_Accessories&hash=item231295a9d7Not true. The later bumpers, used on the fronts of the '52 Corsairs and both ends of the '53s and '54s, and the Darrin are curved differently both horizontally and vertically. They do not interchange - I know from experience.
The Henry J Parts List lists bumper gaurds, (all 4) for 1951 as part number 212295. For the 1952 Vagabond, it lists the same. For the 1952 Corsair Deluxe it lists Front 213326 and Rear 212295. For the 1953, which would be the same for the Darrin, list Front 213326 and Rear 213326.
I can't be sure from the picture, but they do look like the later style. If someone tries to install them on the other style, get out your grinder!