Each Bruni frame was pretty much a one-off, designed to meet the needs of the customer based on Tom's philosophy.
Many of his designs typically used larger than average diameter, thin-walled tubing, sometimes with and sometimes without internal tubes, essentially being one of very few builders in the 90's and early 2000's to use an open-frame design.
He routinely experimented with different frame design concepts -- sleeved take-apart similar who what Bike Friday used on their Family Tandems and more recently on the Rob English tandem one of our BF brothers commissioned, special handlebar installations for his wife, etc.. -- so it without seeing a photo of your Bruni it's hard to know what may be unique about your example.