[morzh]

Well, I did see the difference at some point, but I no longer have any 20 with the original spider, or even the cone.
The 1st ever 20 I restored (1931 version lowboy) had no cone whatsoever. So all new cone and spider were added.
The Deluxe had a good cone but then it had bad field. While changing the field coil, Dee from Alabama Society was not able to save the cone (it was brittle) so he fully re-coned it having added a 45rpm spider.
The rest of the radios with K speakers I have are a 70 and a 90 which have 45rpm type.

So I cannot compare

Does the one you gave me have an original cone/spider or is it also a replacement?

the saddest thing about the 20's output is it is a highly regarded Triode (71A) output that can play QUITE nice (and unlike tetrodes/pentodes has very low THD with only even harmonics plus it is a push-pull). But all that gets nullified with the speaker.

Also, this size cabiet can fully accept H-type speaker and 71A output and the transformer are a good match.