rigby is not a good example because they never made actions. take a look at the FN post war production.
they had have all the machinery from military production to make the M 98 useless now when the assault rifle hit the market. this was the time when surplus mauser's were around in masses and cheap. but was also the time when working hours were cheap enough to make new actions for a price that was a real possibility for the customer looking for a brand new thing.
and dont forget there wasn't another possibility in this time when making a complete new bolt action
rifle than taking a mauser action.