The following publications can answer part of your questions.
1) Title: 119Sn and 13C NMR study of some trivinyltin (IV) compounds and their
complexes.
Source: Inorganic Chimica Acta 1988, 150, 287-291.
2) Title: The 13C and 119Sn NMR spectra of some four- and five-coordinated
tri-n-bityltin(IV) compounds.
Source: Journal of Organometallic Chemistry 1984, 275, 43-51.
3) Title: 13C and 119Sn NMR study of four- and five-coordinate triphenyltin(IV)
compounds.
Source: Journal of Organometallic Chemistry 1983, 241, 177-184.
Have a nice day,
JOE