There are 9 actors credited specifically as playing delegates, of which 7 are identified. Of the remaining 2,
José Granja has one other credit from 1941 listed on IMDb with role, but which I was unable to find. The other,
Agustín Povedano, has 4 other credits on IMDb. 2 of those dating from 1917 and 1935 would be of little help even if they could be found, but I have copies of the other 2, dating from 1953 and 1961, so I'm hopeful I will be able to match an actors from those films with one of the actors below. To be old enough to have appeared in a film in 1917, Povedano would presumably be at least in his 50's or 60's here, which would rule out some of the younger looking ones and make Italy or Iraq seem the most likely.
Since we have 2 further delegates identified who are credited, but separately from those listed as delegates, then it could be possible that one or two more of the remaining unidentified actors could also be playing delegates. We also have one uncredited delegate identified, and from the number remaining there are obviously more who will be uncredited.
The remaining unidentified delegates are:

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- Czechoslovakia
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- Holland
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- Iraq
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- Italy
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- Pakistan
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- Switzerland
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- Tunisia
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- Turkey
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- Yugoslavia
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