Frame - is it straight?

[kundun]

I inherited a 29 Phaeton which originated from Brazil.


Looking at the car, I assume it had a harsh live and little care.



One of the big things, that bother me is the frame. The car must have had at least one accident as the crossmembers in the front have been reinforced and welded as ugly as possible...


Then, to transport the car in a container away from Brazil the frame was cut in halve and welded together again.



So you might understand that my trust in my frame isnt the best.



I've now found a guy who has frames at sale.

But I need a way to check that the frame that I will buy is as straight as possible. I dont have the tools nor the time to straighten it myself.





Can anybody give a advice or a manual on how to check a frame on its straightness?





And, have there been differences in the frames? Have all models the same frame? Must I only look for a 28/29 frame for me?
thanks a lot,