Got some fairly hefty transistors here,  stud-mount package with a
1/4"-28 stud on the bottom of the package.  The ECG book I have here
handy calls that a "TO61" package,  and they list a variant with
an isolated stud (which this is not),  and the version I have is called out
for ECG73,  which does not appear anywhere else in the book.

There can't be _that_ many different types of numbers that use this package
(no numbers are apparent on it,  though maybe cleaning them up a bit will
help).

Anybody care to guess as to what assumptions might be reasonable for these?

I'll bet I can find something to do with them...   :-)

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