I'm no expert, but I'll share my experience with these bolts:
I had a few that were dripping water from the ends. After removing the nuts they were unscrewed with a power drill.
I found some of them to be bent, so they were replaced with slotted pan head 1/4" X 2 1/2" SS bolts of the same style and new washers and nuts. A good squirt of Sikaflex 291 into the hole first, and also tightening all the adjoining bolts has stopped the leaks.
I'd suggest removing one bolt (back it out with some sort of screwdriver to avoid disturbing the bedding), clean it up and see if it's more than suface corrosion. I can't remember if the originals are metric (5mm?) but the 1/4" bolts fit the existing holes.
Replacement bolts are inexpensive, but I don't believe they match the quality of the originals. Stainless steel these days isn't what it used to be :-(
Hope this helps!
Peter
#1331 'Sin Tacha'
