Hi Bucko,
I wouldn't worry about the concern over ""muck".
I have continuously used my Raleigh Record Ace since new in 1984 (that's 36 years) which has a short length of open coil outer cable just running between stops under the BB. The FD is Nuovo Tipo Gran Sport, which is identical to the Record mid-model with no holes in the cage. All I have ever done is drip/spray/whateverlubricatesthatcomestohand infrequently in the ends and along its length and have never had any problem with sticking or corrosion nor even wear (not there in the cable run anyway). I only even changed the FD inner cable when the Rear Derailleur cable frayed and I changed the pair to stainless ones to match.
As to the 'model version' with outer cable stop to hunt for, I am open to correction, but I believe Campag. didn't change reference number 1052/1 of the Record FD from when introduced in ~1960 right up to deletion in 1987 (even if a new 7 digit corporate number system was latterly added).
So you just have to hunt on the images to see if the Record/Nuovo Record FD in adverts has the cable stop you need. I think it is a mid 70's version.
VeloBase.com is an invaluable source of information, I find.
I hope you find what you need, don't be in too much of a hurry and pay over the odds, I am pretty sure I have seen them come up for sale quite often.
Regards,
Robin.