Can anyone identify this 'colnago'?

I recently bought a colnago lo pro time trial frame. But I can't find a reference to it anywhere on the net. the chap who sold me it said he bought it from an ex pro.

here is the description; FORK: 'colnago' is engraved vertically at the top of the crown, no lugging, front brake fits at the back of the fork and the bolt which holds the calliper is actually brazed on to the back of the fork crown. It takes a headseat MUCH smaller than 1".

FRAME: Top tube is pinched at either side and slopes towards the front. Seat tube looks like gilco, has a columbus sticker, it takes a 24mm seatpost. Downtube also has 4 pinches running its length, takes the old aero gear levers on top (cables are internally routed). Upper rear stays curve, and join to the seat tube about 4" down from the seatbolt. They are engraved vertically,'colnago' like the old 'supers'. lower stays are engraved colnago on their sides like the old mexicos. bottom bracket has a strange 'double' lugging. it has the clover cut out underneath.

Front drops are stamped colnago, rear drops are stamped campagnolo.

The front lug is engraved with the clover and it takes 700c wheels

Can anyone shed any light on this affair?
Thanks,
Mike
ps. I'd add a picture but don't know how.

Sloping or horizontal top tube? Similar to this one? Perhaps a Master CX TT?

http://cgi.ebay.com/Vintage-COLNAGO-...12127014r25645

In the 1980's Colnago made a few Profile CX TT syle frames with a level top tube and the 'cloveleaf' 4-indent downtube and a 2-indent top tube. IIRC, those used a conventional 1" ball bearing headset.

I remember various manufacturers experimenting with Delrin bushing (no bearings) 'thin' headsets/headtubes back in the day, but I'm not familiar with Colnago using them. Very possible though.

many thanks for your reply, unfortunately, the frame I have has a sloping, slightly curved top tube. That plus the headset size are what differentiates it from the model you showed. It's interesting though that Colnago did make a time trial frame with those style of pinched tubes (4 pinches and 2)
thanks again,