[MENTION=51742]jdpt[/MENTION] , you are correct to have a 118.5mm spindle length for a triple Octalink crankset of that era (7703 Dura Ace, 6503 Ultegra, 5503 105). Octalink V1 is your ticket. V2 BBs are, to my knowledge, only for mountain. Their spline width and depth are different (and thankfully obviously so) and they are labeled differently. V1's will be labeled BB-XXXX, so a 'paired' Dura Ace crankset to Dura Ace BB would have a 7703-labeled crankset to a BB-7703 bottom bracket. BB-6503 and BB5503 would also work just fine, and as others have stated, much more set-it-and-forget-it. I have both the million-bearings 7700 bottom bracket as well as a few lower-ranked ones. All work well for me!

As long as your smallest chainring clears the chain stay, you are good to go! Clearance, whether it be 10mm or 1mm, is clearance, so don't sweat it unless you have the leg power of 50 track cyclists. I've run less than 1mm clearance on a bike and at 6'5" / 215 can't get 175mm triple cranks to contact the frame (I am certainly not the last word in power output here, but am not a slouch...for short distances!).

There is (another) special place in my C&V heart for Dura Ace triples as they are so rare and intriguing. The Dura Ace to please the eyes, the triple to please the knees, and leg muscles, and heart, and lungs.... There is a 7803 crankset for sale at my LBS and it's my length and for a great price. Very tempting, but I already have a 7800 crank on a bike I really like! Tyranny of the immediate opportunity! Looking forward to seeing your Paramount completed. 50th Anniversary, mmmmm...