Well folks. I've managed to find the correct type of handlebar grips for my Lightning.
I've mentioned before that I had previously used a pair of replacements that looked the same, but were 15mm to long. Well. I've found another pair that are also 15mm to long, but they can be dismantled, so they can be cut to size. The Eagle motif on the ends is similar, but not the same. They also have "Roadhawk" written on them. The originals and the first replacements just had a blank space.