[Elecraft] capacitors

[n3drk]

I cannot seem to locate a couple of  capacitors. They are c73- a 47, c71 and
c174 both 82's. According to the elecraft website builders resources,
capacitor marking table, the 47 can be marked 470 and the 82 can be marked
as 820. Question is can c4 or c8 marked as 820 be substituted for c71 and
c174?

In addition to that is i have two small odd looking parts which look like
capacitors. They are green and have a black marking on top with no
identification at all on them. Can someone tell me what these two components
are and possibly the values.

Thanks
john