WASR front sight elevation question

[Caribouriver]

First day out, sighting in. Using the $5 sight adjustment tool that works fine on SKS, I managed to shear off one of its fingers trying to move the front sight post. Wouldn't budge up or down. Is there a lock screw on the front post? After I got home I saw that there is a grub screw if I look up through the hole under the steel dowel of the windage adjustment. What is that screw? What does it do? Does it lock the elevation post?? The windage adjustment? How to you loosen/tighten it? It's really in a tough spot access wise. Other then the problem with the sight adjustment, the WASR shot better than my M1 carbine. Although POI was not POA, It was grouping 3" @ 100 yds from a rest with Yugo surplus. Thanks for your help. Photo attached with edit. What is this screw?

[projectalpha]

There's no locking screw for the front sight. Get the AK buttstock cleaning kit. It comes w/ a front sight adjustment tool. My $5 sight adjustment tool broke in the same way yours did. I just use it for windage now.