Which pens suitable for Agenda PM pen loop?

Lelliebunny, or anyone else who knows - are the Spacepen with clip/stylus and the regular Spacepen the same dimensions, roughly?

I haven't heard back from either of the eBay sellers I've contacted regarding international shipping, but the UK division of the company themselves did email me back to say they had only the Spacepen with clip/stylus in stock. It's this one: http://www.gbapen.co.uk/products.aspx?category=F_STOWAWA&Make=Fisher Space pens

Does anyone know if this pen will fit the PM agenda?