In my opinion,if the relic item is in danger of falling to bits then restore it!
I have a panzershrek round that was fully restored(took 3 years to get the damned tailfins back from a pal,long story!) but it is looking very good. Im going to get my tattoo artist pal to paint it and add stencills.
If i had not done the restoration then it would be just be a crappy old pile of junk.