Worth the effort?

Valve springs tend to loose their strength in hot fires.
Yes, but, this fire doesn't look like it got that hot to hurt the valve springs under a steel cover. You would have seen more items melted down for that to happen. I mainly see plastic, rubber, and wiring damage....and mostly on the driver's side. There are some items on the passenger side that didn't even get damaged, including the plastic oil cap in the valve cover. The upper radiator hose is still there, and the battery might still be good.