Stuck valve springs

I am swapping the heads on my 66 Mustang 302 and am having trouble removing the vavle springs on the old heads. I wanted to use the springs, retainers, and locks again for the new heads but some of the springs were very very stuck. The valve spring compressor is kinda old but I dont think its broken. I eventually got all the springs off but I am now hesitant to re-use them because I am afraid they are damaged. They do have scratches and stuff but I think that is from the valve spring compressor slipping while trying to compress them. Also I was wondering how important it is to use the rocker arm, spring, lock, and retainer on the same cylinder that they were on on the old heads. I know these are alot of questions but I hope you guys can help me. Thanks in advance, Mike.

Thanks for your help! yea i guess it was probably just the retainers that were stuck. Do you have any advice for installing the springs on the new heads? I was told how to do it but have never done it myself. From what I understand I just compress the spring and place the locks on the groove in the valve stem and slowly release the pressure on the spring so the retainer goes around the locks. Does that sound right?

Thanks for the help guys. I am happy I found this website with so many smart people on here. I'm sure ill have more questions to come