I have done some asking around on this subject on a German classic bike forum. The only name that came up was Gerry Howards and also that he stopped due to illness. And also that this was a major problem….
They also gave link to a website with some info on HAJOT pumps that could perhaps act as a replacement. I do not know anything on the availability of these pumps.

Left Pilgrim, right HAJOT
Here is the link
When I find out more I will post here.
Cheers,
Erik
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When I was on this website I found some very nice pictures of Scott speedway bikes. Here an example:

More in this link
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