NOS Shure V15 type III cartridge opinions

I know this sounds crazy but going thru boxes stored in closet for the past 40 years and found one of these I had purchased in 78 as a spare and never used. My question is should I open it up and give it a spin on my vintage TT or keep it to replace my in use cartridge until it goes south or open it install to see what happens? Wished I had another headshell. I read this was the best mm cartridge build, great all around sound and unsurpassed tracking. 
Or put on market? I'm leaning toward trying it out but then again?