here in connection with literary hereafters. We should also mention this Anderson novel in connection with fictional treatments of the English Civil War. Ghosts of Cavaliers and Roundheads and of the Leveller Thompson have just come on stage in the multi-dimensional hereafter of Alan Moore's Jerusalem that I am currently reading.
However, I find that the English Civil War has already been discussed to some extent on Poul Anderson Appreciation. See:
Cavaliers And Roundheads
Peter And Poul II
Prince Rupert And Other Matters