What you saw were cable stops/cable adjusters that bolted onto shifter bosses that were brazed onto the downtube to mount downtube shifters. Your bike apparently has stem shifters and those stops are only housing stops. You can mount brifters and use these housing stops but will have to provide an in-line cable adjuster for the front derailleur. Most rear derailleurs have an adjuster built in.

Not to burst your bubble but have you purchased the brifters, both derailleurs, cassette/freehweel, chain and perhaps the new wheel needed to make this conversion? You may be surprised at the cost.