yeah, some of them were refered to in part with a current rating, others (about thumb size) with 3 to 4 cells of wave wound coil on it were min 12 quid and 26 quid for the 4 cell one, whereas the one pictured (illustrated) in the book looks to be a 4 cell choke with a laquer coating, again, sadly no ref as what value it was or even a part number
I imagine that back in the day, one could walk into any sort of radio dealership and ask broadcast band RF choke and be handed one straight away.