I basically did that but am doing the reverse! Taking parts from the wrecked one and putting on the other one! Hell the 97 is in better body shape than my 99 was BEFORE the accident!
I figured the dash was a tough job, the airbag punched the whole thing upwards from divers side to passenger side. I never thought an airbag would do such damage!! Man no wonder insurance writes off cars after air bags deploy!
The guy stopped calculating damage costs at 3500.00 and that was just labour and he had not looked under the hood yet. I am betting one cocrete post at less than 20 km/h was over $5000.00 damage!
So I paid 800.00 for a 97, take parts from the 99 and sell the rest. See my thread under parts for sale for details on that!
I did see a guy on Kijiji selling his Bonneville for $600 for parts because his head gasket blew. I have offered him mine but he has not gotten back to me yet.