Ah your help pays off again, the vanes are indeed shorting on both caps. I'm unsure if there is a way to clean them perhaps? No idea why they are shorting, but I suspect that this must be the issue.
I don't particularly know why I chose.it, I seemed to have a lot of the little components and it seemed not overly hard to make but a challenge for a novice like me where I could learn a lot. In hindsight, I should have picked a two tuber. The book I have which features it is linked below (page 9):
PDF for How to Build Radio Receivers
It is also featured on pages 11 and 29 in this magazine too 10 years.earlier in 1940:
PDF Radio and Television Magazine