Thank you Ed once again for your good advice.
I haven't done a batch of rear sight springs yet, but just finished two, which I am using as a pair.
The tape measure metal is too thin and does not have enough spring power otherwise.
But with two layers, it works well (although it won't win any beauty contests!).
Hi,
The original springs had the ends folded down as shown, can't see if your's does;
ATB, ED