Oh no…sorry to hear that about Poetoe!
Here in Canada I don’t see a lot of sun induced diseases like cutaneous squamous cell carcinoma. Since I’m not trained in classical homeopathy, I also don’t have any experience with Cinnamomum or Tonsilla. Many people think that NSAIDs will have a beneficial effect (there are a few studies that show this), so the metacam he is taking might be especially relevant for him.
Have you considered or discussed cryotherapy with your vet? The remission rates are supposed to be quite good using this method. You would be spot freezing the affected part of his nose to try and eliminate as much as the cancer as possible.
So it’s a bit of pain (you are freezing the tissue) for potentially a lot of gain. There are barn cats in Canada with unintentional cryotherapy when the tips of their ears get frostbite. No joke.
All to say while it sounds icky, worse things can happen, right?
I’ve seen regular human G.P.’s with a cryogun treat skin lesions this way. Essentially just point and freeze at (-50 to -60). The equipment and technique don’t look especially complex (they are hand held and portable), so if there is no specialist in your area, I would suppose that a G.P. could handle it.
No matter what happens, I’m glad little Poetoe have people that care about him.