Hey Fran --
Thanks for the challenge -- it's nice to have some fun every now and then.
One peculiarity I noticed. I'd never heard of this Mr Peake, but he must be American, anyway. In fact, the rhyme tunes/moons works only for American English speakers. /t/ is a coronal and there's a different pronounciation in AE and BE for /t/ when it's located in front of /u/. In AE it's pronounced /tu/, whereas in BE the pronounciation is /tju/. So, in the USA /tuns/ is a rhyme to /muns/; in UK, /tjuns/ is not.
I mean, it's unbelievable all the stuff a poet must take into consideration before writing a rhyming pattern.