Thank you for your offer. Of course it is very inciting and it would a great honour to me. Thank you also for bringing my post to light again, as I gathered some more articles on the Tannenbergbüchse.
According to Joachim von Wlassatys article Nachlass der Raubritter - 600 Jahre Tannenbergbüchse in Deutsches Waffen Journal 6/1999 the ramrod was separated (and the loading of the gonne and the rest of the survived tiller were removed from Tannenbergbüchse
) before the Tannenbergbüchse was transferred to Germanisches Nationalmuseum in Nuremberg. As far as I interpret the article the ramrod (along with other finds) was probably lost during bombardements of Hessisches Landesmuseum Darmstadt in 1944