It was a Missouri Meerschaum Diplomat, with a bent stem, filled with St Bruno Ready Rubbed (a blend I'm very familiar with). I picked the St Bruno as I thought it was a good idea to try something I already knew, so that I'd be able to discern what difference, if any, the cob made.
I left the supplied Medico 6mm paper filter in and enjoyed a very nice, cool, dry smoke! The Diplomat is finished with Plaster of Paris, for a smooth bowl and whilst it's about the same weight as my two small Petersons, at 46g, it felt a bit heavier when clenching. This might be due to the stem having only a slight bend, relative to it's length.
Up until now, I've not bothered with a cob...having been able to pick up quite a few good quality "estate" briar pipes for not much more...but now I can see why they are so frequently recommended as "starter" pipes.
I was so impressed that I'm going to get a few more, along with some spare stems, so that if anyone at a meeting wants to try a new blend, they've got a neutral platform to try it in.