No, Vstock does not accept bank notary stamps. Better wait as LAHO is currently working on this issue as they discovered that some shareholders have that problem. However, you better contact LAHO and let them know your situation so they know how common that case is.
Medallion via esignatureguarantee.com is available for US citizens only. If this is a problem to you, I recommend contacting LAHO and Vstock for a solution.