I may be incorrect but, unless it has changed recently, Flybe Nordic operate what used to be Finnair's Embraer and ATR aircraft.
I think Finnair and Flybe own about 50% each.
There was talk recently of the partnership ending and one side was trying to dispose of their stake for 1€.
If the Flt no. is AY2*** then it is a Finnair flight operated by Flybe Nordic using, probably, an E190.
In which case the baggage allowance will be Finnair's.
If it is BE*** then it is a Flybe Nordic flight entirely and, probably, bookable through BE website.
You may find it may be bookable and cheaper through ba.com.
Finns tend to use "Expedia" or "Kilroy" if they go through one of those "intermediary" websites.
Personally, I wouldn't touch anything to do with Greeks - bearing gifts springs to mind.
Just tried it ba.com allows booking on BA6003 - the ba codeshare operated by Finnair using Flybe Nordic metal on this route.
You won't get free drinks, a la BA, though!!