Which of these two Girard Perregaux?

BlueOtter

This is a photo of my Girard Perregaux sea hawk from the 90s, with the reference 7300. I previously pointed out that there were sea hawks made during this period with the Lemania movement and that belonged to the 7100 as rightfully pointed out in the watchprozine link that arcadelt has posted on the thread. 7100s were produced from 1988 to 1990, and 7300s were produced after that. However, I do not know when they were manufactured until. For the 7300, exclusively ETAs were used. It is trickier for the 7100 as both Lemania and ETA were used so I guess the only way to actually find out if your watch has a Lemania or an ETA would be to pop the back open. Another difference was that the 7100 had a sapphire bezel while the 7300 had an aluminum bezel.

So the conclude - it's really tricky to find a 7100 with the Lemania and I wouldn't really bother at all to begin with for 2 main reasons.
1) There will be an associated premium with it which simply is not worth it given its rarity, and the Lemania is not a more superior movement per se in terms of function.
2) Unless you happen to chance upon it by a stroke of luck, it's going to take a long time for you to find one with the Lemania. So I wouldn't bother unless you are a diehard GP collector that for some reason, needs a Lemania powered 7100 to fill a gap in his collection.

Another word of caution as an owner of these watches - check for the condition of the crown with the seller. These watches all had screw-in crowns and a lot of them get worn out over the years and finding a replacement in the aftermarket is impossible, which makes a full overhaul back to Switzerland the only viable option for getting a crown. I have been there and done that, and the associated costs ain't pretty. On that note, make sure that there are no issues with the bezel insert as well.