Be careful with lyman frizzen springs,I purchased two from RMC, $20 a piece,the first one broke on installation and the second one broke the first time I opened the frizzen
after the installation. RMC would not do anything for me ,the implication from them was that I did not know how to install the spring. Those springs at that time were improperly tempered,had i known that before I tried the installation I would have properly tempered them myself ,so I was out $40 and still needed frizzen springs.
Then from the help of a friend we made our own,I cannot explain the process of doing that here,but now I have springs that work and the know how to make more.
I would suggest you take the lock to a shop and have them install the spring,I know it's a simple task,but if they break it they own it, if it breaks when you do it (oh well),your on your own.