They're very nice weapons Primarch (I also had a set of each of those weapons too) but they definitely aren't Adeptus Titanicus era weapons. They're nearly all unreleased weapons from the Mark II Warlord Titan, the less common metal 'milkfloat' version from the SM 2 / Titan Legions era. Here is a photo of my ones on a couple of those titans -
http://img126.imageshack.us/img126/862/titans.jpg The chainsaw arm is just a regular released AT titan weapon then.
I would LOVE to own a copy of a MK0 titan. It'd be too small to use as a Warlord alongside my truescale titans, but I'd probably count it as a Reaver in game terms (the AT era Warlord had 2-4 weapons). It's an old model, but well designed and looking great and a piece of epic history, familiar from the early horus heresy battle scenes.
Mind you, here's an even earlier prototype epic titan:
I guess you could call it the Mk-1 Titan? It's from the collection of Bryan Ansell, sculpted by Bob Naismith as a prototype titan during early playtesting. See here for more photos and details -
http://eldritchepistles.blogspot.co.nz/Here's a photo of another one on display in a GW cabinet at a recent Forge World event, proving it is genuine:
