Hello Inna,
I live in the Netherlands and I am one of the owners of the PH-RLA.
The link you gave brings you to a Saab forum for the Saab CAR.
One was telling that his grandfather was an instructor on this aircraft and thought that it used to be an aircraft like the RLA.
But it is an 91B and not an 91D so a few on that forum know more about cars then aircraft.
I phoned the owner and she told me that the RJB was build in 1954 by De Schelde. First registration was SE-XAU.
From 1958 till 68 it was property of Lufthansa with registration D-EBUC
From 1968 several German and Dutch owners. Presently for sale and stationed in EHMZ
Here:
http://www.transalaero.com/rjb.html you can find some more info.
Regards, Sjoerd