I have to disagree with the first response.
The best thing you can do is first MEASURE what you have. Remove the rear wheel, and measure the distance between the drop outs. I would be that it is 140mm. Other possibilities are 135mm and 145mm.
Next measure the Over Locknut Dimension (OLD) of your present hub.
Sheldon Brown's Bicycle Glossary N - O
The Samba has been around since 1993 - there have been changes over the years.
Once you have the measurements, tell us, and many suggestions will come.
Our Trek T50 has 140mm drop out spacing. When the original rims cracked (we are not the original owners); I decided to convert from seven speed to nine speed. I went with Wheelmaster 40H cartridge bearing tandem hubs, which are 135mm OLD, and added 2mm of shims (precision washers) to each side. This has worked well.
(note the Wheelmaster hubs are available in 40H and 48H).
Also see:
http://www.bikeforums.net/tandem-cyc...ease-help.html
Regarding "re-aligning"; this is usually called "cold-setting". Research this carefully, many people have done it. I have done it on several single frames. I would not do it on a tandem frame.