Harrison M300, no taper attachment and not likely to buy one,
bridgeport. Quantity maybe 4 at the moment and more occasionally. I
would make some simple tooling for it if it didn't take more than a
couple of hours for interest sake. It not really a commercial thing.

Fred R wrote:

What kinds of machines do you have for this job?
How many do you need to make; in other words, how much is it worth to
build some tooling/fixtures?

What I'm toying with is the idea of a custom travel rest with a good
heavy sleeve bearing for the 1/4 stock, sturdy tool on the compound.
Some method* to produce the taper from small end to large end as the
slide moves toward the head end. Take the full cut in one go, like in
a box turning cutter.

* methods could range from CNC to judicious handwheel turning based on
a table of dial marks vs slide travel. An actual taper attachment for
the cross slide would make this a piece of cake, even avoid eating it
all in one whack.

Sounds like fun to someone who doesn't have to do it!