Yes, with the Spritze-Gambo db Davis will import to the Reds' organization in 1980.
Download the SG db from ootpmods.com (look under Databases - it's the first file listed). Save the file to your computer and then unzip the file. Then put all of the unzipped files into your OOTP stats folder (allow the SG db files to overwrite the existing files, but do not delete all of the other files that are already in the stats folder)... You will also need to use the transactions.odb file from OOTP v12 for this to work the way you want. You can get that by downloading the v12 demo, or someone can probably send it to you (I could later)... When setting up your game you'll need to be sure to choose Neutralized Stats instead of Real Stats (I don't have the game in front of me but when using the historical wizard for setting up your league, it's on the first panel).
(Note that it isn't the OOTP 12
rosters to which I was referring, it was simply the historical transaction file from OOTP 12.)
Before doing all of the above with the SG db, I would first recommend do a simple/fun test using the OOTP 12 historical transactions file using the default OOTP14 database (not the SG db) and then running a test version, starting in, say, 1970, using real transactions and setting Retire Accdg to History OFF, and then just letting the game run, stopping whenever you want to see how your Reds are doing. But don't fool with much and don't yet worry about uniforms and ballpark pics and reading every single news item. Just check things out from time to time (especially at the end of each season) and get a feel for the how the game works. This will also give you an idea if you will have what you'll need in terms of Reds' minor-leaguers by 1983. If so, you're good. If not, then you can try the SG db. (The downside to this is that Davis will "magically" debut in 1984 rather than in 1980, but you will have fun getting acquainted with things.)
Finally, if you are considering using the SG db or the Spritze HS one, here's some recommended reading:
http://www.ootpdevelopments.com/boar...-ootp14-2.html
OOTP Community Wiki | Historical Databases - summary
OOTP Community Wiki | Spritze's db for OOTP14
OOTP Community Wiki | Spritze's db vs Spritze-Gambo
Good luck!