It would help if we could see the actual machine and not just a bundle of cables?

The "stinger " looks like something off a battery charger.

Looks like hand crank on top to change amperage with ?  Reckon it had a cover on it at one time ?  I don't have any idea right now what it is but another pic with cables off might help.

Victoria,

I seem to agree with the other gentlemen's responses.
However, I dare to guess that your Dad's first machine might be a so-called 'Moveable Coil Transformer' (for Shielded Metal Arc Welding - SMAW), which btw would also confirm "FixaLinc's" recognition of a hand crank.
Differently to 'ctacker' however, I would suppose the "stinger" (which I suppose to be the electrode holder?) to be the 'work-' or 'workpiece clamp'.
The fact that there's (apparently) a certain amount of weld metal deposited on this part might indicate that your Dad was igniting his coated electrode before he was starting his actual welding operation.
That is. A "warm" electrode tip was often found to improve the arc ignition vs. a "cold" one.
That's especially easing the welder's life as far as 'Alternating Weld Current' is used as supplied by this/your piece of equipment (weld transformer).

I will attach both a modified image of your photograph + another image/sketch which, hopefully, makes clearer to you what I have tried to very basically describe above.
An excerpt from the AWS Welding Handbook "Welding Processes - Part 1", Vol. 2, 9th Ed., (2004); I very much hope though that the American Welding Society will not be sueing me now for using this sketch without asking the copyright holder for his written permission.
As a matter of fact, however, the Handbook named is a very helpful source of information in respect of answering questions to especially welding machines and peripheral equipment.
Hence, I just can recommend reading it. It's definitely worth its price.*

By all means. Have fun with testing your Dad's Shielded Metal Arc Welding machine.

*) @ 46.00: No, this is not a hidden advertisement. :)