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?
128x128gillatgh
To all that have responded,  you rock my world.  Thank you so much for your input/suggestions. 
I will try the NOS as is and if need be get the best rated albeit most costly stylus if needed. I think I'll start by obtaining another headshell first for ease of swapping out between cartridges. It's also most economical. 
Thanks again

Consensus seems to be that the suspension for the stylus may be suspect after all this time.
For something this old you can count on it, and its not something you can see with a microscope. We're not talking about the stylus- the suspension is at the other end of the cantilever.

I would get the stylus replaced before taking it seriously! IOW if you like it now, it gets better :)
Ralf it’s no penalty for trying existing one first
The way original needle sounds is unbeatable by any aftermarket .
In room conditions without usage it will stay just fine for century...
the suspension of most vintage needles is visible with pocket microscope for jeweler
Thank you dlcockrum for the link to jico. If need be I can order the vr35e or vr35 he directly from them at 79 or 119 dollars respectively. If I do need to order I will go with the HE hyper eliptical stylus.

FWIW, while surfing found a NOS the seller is saying is new in box for 499.00. Looks exactly like mine. Y'all go get it.