[slamdvw]

...Can you shoot us a couple of pics of this thing?

The primary windings (generally) will be a finer size of wire than the secondary.

Primaries will also have a higher reading than the secondary. EXAMPLE: 1,000 (1k) ohm for primary, 10ohm for secondary.

Those "heat sink type things" might be the secondary taps... Then again, they might be the primary taps... Pictures will help a BUNCH.

 

[slamdvw]

Just measured... Primary side - around 1 ohm. Secondary Side - about half ohm.

Welder - Hobart TR250. Granted, it don't have a multi-tap transformer ( magnetically variable ).