There are quite a few companies that still offer that option today....
http://sviguns.com/
I don't know that there is a practical application to it ...unless you intend to wear heavy gloves in the winter or something.../ but I'm not sure how much more room it gives you, if any frankly. I was shooting one of my 1911's today, with a conventional trigger guard, with gloves -with no issues.
There were some instructors - years ago - that were teaching some optional grip techniques - where the off hand fingers wrapped around in front of the trigger guard...so maybe whoever had this done /liked that grip style. I never thought personally it was a good technique...but a lot of grip styles have come and gone over the years...
But I wonder if that trigger guard will fit into most 1911 holsters...?? I don't know ...
I don't know for sure - but my hunch is, that modification was not done by Colt / but you'll have to contact Colt and see if they ever offered it as an option on a special order.