Så här såg svaret på mitt mail:
Hi sorry for the slow reply, we have had this a few times before, it seems there was a few months in 1971 model year where they kept the early crossmember, but changed the chassis rails. If this is the case, then the panel we sent you would be 40mm too wide, apart from that everything else should line up, we could send you a later cross member which would be the correct width, but all the holes and notches will be wrong, we have never managed to find an original one to use as a template to make it correct, so i think the best way is for you to shorten each end by 20mm on the one you have, obviously it is no probmel to refund the part if you cannot use it.
One day we hope to work out the changes in 1971 but we dont have enough information yet, sorry for this.
Thanks regards Rick..
Jaha..otur,bara att korta på då.. 
I hope to arrive to my death,
late,
in love,
and a little drunk..