What problems are you experiencing?

However, with the information provided... With those chainrings, you are running a mountain/touring crank, so the Deore (Deerhead) would be a better guess than the 600, which would be a road derailleur.

Actually another point came to mind... Is the front shifter indexed or friction? The cable pull on Shimano front derailleurs are different between mountain and road, so if indexed, there is a difference. But then again, pre-9 speed Dura-Ace were oddball too, but I have read that concerning the rear derailleur, so I have no idea if the same sort of issues impact the front derailleur.

So basically, I don't know. If you are running friction, then I would definitely look toward the deerhead before the 600.