Dedacciai 18MCDV6, also known as Dedacciai Zero HT Koncept tubing. It's a high quality steel. My frame is very responsive. Looks like Dedacciai made it for De Rosa, judging by the UK EBay listing.

The model below my Moser sold last week for about $500, frame and fork, no headset/BB. Same frame material. The frame and fork are probably about 3.6 lbs.

Have you seen the frame in person? I would imagine that the workmanship is superb. It is on my Moser.

Post a picture if you can, that would help.

I wouldn't hesitate to buy one, if the price was right.