Μᾶρκος ὁ Φώσφορος τῷ Ναθαν τῷ Σιδηρεῖ χαίρειν πλεῖστα.
I agree with Stephen that your usage of τό is spot on. I tend to add the Greek quotation marks just to make things more explicit. As far as “mis-spell,” this came up on another forum, but I forgot what we decided. There is nothing wrong with ἀνορθογράφω (I understood what you meant) but LSJ lists ἀνορθόω as “I set up straight, I correct,” where the alpha nu is not privative but is the preposition ἀνἀ. So there could be some confusion. Plus, I’m not sure, but I think this word would be augmented ἀνωρθογράφη, not ἠνορθογράφη, although the latter is not impossible. I would use the simpler κακῶς γράφω.
σήμερον μὲν οὖν ἐν τῇ ἐκκλησίᾳ μου εἶδον χάρτην τινα ἐφ’ ἣν τὸ «δημοκρατία» κακῶς ἐγράφη ὥς τὸ «δμοκρατία.»
δμωκρατία would be government by female slaves (δμώς.) I say they couldn’t do worse than some of our politicians.