Leon,
Probably ANY reactor, choke, inductor, etc. that can handle the welding current would improve the DC arc behaviour.
The buzzbox is a single phase device where the rectified DC goes to zero 120 x per second. It is the inductor's job to "fill in the gaps" and prevent the current from dropping to zero. The size of the inductor, in milli-Henries, depends on several factors. Suffice it to say that a single phase welding transformer requires a larger inductor than a similarly sized 3 phase transformer, or a relatively "high frequency" aircraft generator. (I'm referring here to the number of DC pulses per second and whether these drop to zero). The advertised reactor is for use with an aircraft generator and I suspect that a relatively small inductance would suffice here...my guess.
The welder we built has about 4 m-H of series inductance and it makes for a very smooth and continuous DC arc where it matters, say at currents less than 60 amps or so. This inductor, a re-wound transformer really, is heavy, I'd guess 35 to 45 lbs.
Just a tip on how we arrive at our projects. The occasional project is planned in advance, and material is acquired with this in mind. Critical items are purchased, such as a piece of 1144 stressproof steel for a single-piece crankshaft.
We are proverbial pack-rats and have the sheds, garage, and attics to prove it. Every now and then we get the notion "to do something" with the "rubbish", apart from throwing it out. That's how the welder got built. My Dad bought the Lincoln buzzbox in 1969. The inductor/ transformer I got from the scrap pile at the university 10 years ago...it had a short in it. The original diodes and heat sinks we were given. The oil furnace ignition transformer was from my parent's house when they got a new gas furnace in 1972. Bits of welding cable were accumulated over the years, as were odds and ends of brass, copper, nuts and bolts, etc.
Once the project is identified we assess what remains to be scrounged, and we buy the rest. For the welder this was primarily the stuff for the heat control, the high voltage capacitors for the high-frequency arc starter, and the by-pass capacitors. These were rather expensive but after having fried the first set of power diodes we didn't want to take a chance. And a couple of fans to blow air over the heat sinks. We modified the original buzzbox cabinet and fit everything inside except the HF arc starter.... which is assembled in an old 286 computer cabinet.
Anyhow, it keeps us off the street and out of the bars. And a tolerant wife is a definite asset.
Wolfgang