Could be an old style signature, here is my IP from 1994. He certainly does not sign like this anymore and hasnt for a long time(in fact he hardly signs at all anymore). My advice is to find out when the signature was obtained if possible.
thank you very much for your help, I tried to contact the seller but unfortunately he too bought a few years ago and he doesn't know where he got it, comparing it with yours looks quite similar. thanks again for your help.