Pausanias (Description of Greece, IV.33.2) quotes two (almost complete) hexameters from Eumelos, a poet of the seventh or sixth century BC.
τῷ γὰρ Ἰθωμάτᾳ καταθύμιος ἔπλετο μοῖσα
ἁ καθαρὰ<ν κιθάραν> καὶ ἐλεύθερα σάμβαλ’ ἔχοισα.
The underlined parts are certainly not Ionic, while those in bold either are (-ons- > -ois-) or could be Aeolic (Hooker 1977: 61 and 96, n. 116). In fact, ἔχοισα is an alteration of the transmitted form, ἔχουσα, whose warrant comes soley from μοῖσα (or Μοῖσα).
Sapph.110a.2 has σάμβαλον for σάνδαλον, but so too do Call.fr.631 and perhaps fr.297.4 and 8, Herodas 7.60, and Diotimos, Anth.6.267.
Beekes cites the 'coriander' pair of κορίανδον and κορίαμβλον (from a glossary and from Hesychios respectively), alongside κορίαννον the form known from literature.
The lexicographers gloss σάμβαλα either with σανδάλια (with the diminutive, not with σάνδαλα !) or with ὑποδήματα. They make no comment about dialectal affiliations.