vinnebones

what would you offer me for this?

PLEASE HELP, this has been on a shelf in my nans for as long as i can remember, i think its a Lachenal but i have no knowledge at all really about these things, i have it listed on ebay as we speak and i have received more messages for this in 1 day than anything i have ever listed, if someone could please enlighten me on the origins i would be greatfull or even better make me an offer to buy! Also i have attached a photo of a Lachenal that looks very similar!

please help! i dont know what make my concertina is but want to sell it! any offers or advice please?