It is a Gipiemme (GPM) seatpost. The script "G.P." on them always seems to stump folks.
Nice enough posts in their own right, they came in plain and fluted varieties. The seat rail engagement is quite positive and doesn't seem to suffer from slipping problems that some other single bolt designs have.
Charlie Young
Honey Brook, Pennsylvania USA
> Hi Everyone: I got a hold of a dandy 1982 Holdsworth Professional and it
> had this seat post on it with the only Identification was a two letter
> signature that I have never seen before. Can you folks take a look at it
> an let me know if anyone knows what this is? It is item #140359253816 on
> Ebay. Thank you
>
>
> Jim Abt
> Wausau, Wi. USA