May require using shouldered screws so the spring ends have freedom to rotate or that is what I found on a similar 600 series deck as both 7 and 8 are moving arms. I have seen where regular screws have been used as replacements.
Same problem here.
I went down a slightly different route by using a longer bolt with a hold down nut & a sliding sleeve over the bolt.
I rather think here was a bad batch of springs hat were not heat treated properly around a while back down here.