Saying Hubbard came in in 1955 is flat-out wrong. #36 is quite clearly Hubbard, and looks to me to be almost purely Hubbard; similarly issues 42-47 are obviously Hubbard. Everything I've seen up to #33 is just as clearly Kelly. However, issues 34-41 (other than the 36) seem to be more up in the air.
#34 and #35 don't look that much like either Kelly or Hubbard to my eyes; except where they do.

Thom from Whirled of Kelly doesn't think Kelly had much to do with either of them; JVJ has suggested that they're roughly penciled by Kelly. I will mention that I don't think there's a chance Kelly actually WROTE the issues, with the 34 in particular being a mess and the storyline in 35-37 suggesting some serious course corrections. 37 and 40 look to be mostly Hubbard, but if so he was doing the issues far more under the influence of Kelly than usual- and noticeably more than in the #36. I cannot completely reject the idea Kelly had something to do in those issues, but I also can't say with any certainty he did. I have not seen copies of 38, 39, or 41.
If you know of ANY scans of Peter Wheat that didn't come through me, please let me know! As far as I am aware I'm the only person who has scanned anything other than Peter Wheat News #61, and even that was obtained by me talking to the seller on eBay (who was cool enough to provide good scans of the issue when I didn't win it!)