The problem you have is that odd ball sized aluminum
cylinders just aren't popular anymore.  I have the same
problem.  I have a super 80 that was never sold and sat in a
distributors warehouse until a few months before the hydro
expired.  Basically, untested, it (and yours) is worth about
the value of the valve $25-50.  If you go through the
trouble and expense of getting a hydro, it is still only
worth $50-75.

Since your old 100s are big ol' boilers and not in favor
with the crowd here, you will probably have an easier time
selling them on Ebay or in your local penny saver.

Just my $.02

$50 the pair and you pay the international shipping to New Zealand.

so probably not worth your while. I'd advise give Ebay a try.

rhys