Jelco 850 total weight

montaldo, aren't replacement springs available from SOTA?  Also, I read some years ago that the springs can be re-tempered by boiling in a pan, immersed in brake fluid.  You might check those solutions, then you wouldn't need to be concerned about the arm weight.

Yes but the springs seem to be fine for now and I would like to avoid taking it apart if I can help it.

 Part of my need to check weight stems from advice I have received that some arms are simply too heavy for the sota suspension even if it were brand new. So I just wanted to have a reality check that the 850 is not much heavier than the 750.

I have both arms and while I haven't weighed them, there's not that much in it from what I can tell handling them. 
The 850 improvement in SQ is worth replacing your springs if there was a weight issue.

Place something that weighs a few grams on the plinth and see springs can take the extra weight!