Matt, I think that the vast majority of today's modern Mauser-like rifles (incl. Rigby) buyers are "Mauser Oberndorf illiterate" and are not even aware that original Oberndorf commercial actions were made into different sizes; there is therefore no obvious reason for modern manufacturers to multiply production lines and incur additional costs that would impact on their profit. I am sure that rifles produced nowadays with such modern actions are well manufactured however they will always, for those who know, lack the charm of original pre-WW2 rifles. On the same way than a pair of Crockett & Jones manufactured in Eastern Europe (this has not yet happened) would never be the same than an 'original' one manufactured in Northampton!
Louis