The biggest difference between original and repro round bead fuzzies is the repro ends appear as though they are straight cut on the ends, the originals almost appear to have been cut using a tubing cutter, the round tube is "bullnosed" meaning the edges of the tube appear to have been rounded over
VS having sharp ends.
If the customer didn't supply NOS fuzzies I have used a diamond file to roll the sharp edges making the repro appear like originals.
This is the best photo I have of a repro, if compared to an original or NOS the ends give them away.