Hi Robert,
I don't know about all of the first contract Finnish Lugers (the 8,000 purchased in 1923), but at least some had refurbished WWI parts used in their manufacture. The one I submitted pictures of for the Owners' Corner had a date (or something) over the chamber ground off. In those pistols where the date was completely removed the only way to tell a date ever existed is to examine the receiver ring to see if it is out of round due to material removal. The 1923 Finn pictured in the Owners Corner has had so much material removed from the receiver ring that the top of the receiver ring is almost flat.
As an aside, there is a scan of the advertisement for the Finn M23 Luger pictured in the Owners' Corner as the last image in that display. Here is a similar period ad, but for M23's converted to 9 mm Parabellum by the Finns.
Hope this helps.
Best regards,
Kyrie
http://boards.rennlist.com/upload/Finn_pistols.jpg