Well, if we are talking the dockside switcher- yes it does kind of matter IMO based on the fact a local friend who refurbishes and sells a lot of them has taught me over time. I might mention, I also end up repairing a fair whack of the reverse unit boards in this- if/when the motor burns up, draws high current, and thus the reverse unit transistors go into thermal runaway and failure.
The early ones used a type 1 motor, and that is no longer available. The diecast frame and mounting hole were changed for a type 2 motor series that at best requires modification of the older chassis to fit.

One example https://www.lionelsupport.com/...w-Whistle-71-6-38622
I want to be clear, I'm not saying these are bad engines. What I am saying is, we are talking about an early version, with a type one motor, never run and the grease and lube might not be ideal, and then knowing limitations of the drive line and lack of any heatsink on the transistors, along with propensity to thermal runaway- and then it's not just bolt in parts situation for what is still available.
Again, I know someone who sells these all gone through, refurbished and done right. I'm not even trying to promote them,
I'm just saying, if you are asking and have a choice, I would know what I'm buying, the exact condition, do I have the skills to inspect, relube, possibly take apart to maintain this engine? I personally also consider long term parts availability as a plus or minus in my buying decision.
Again, I'm not saying never buy an early version. I'm not saying it's going to fail next week or even next month.
But I would factor in the "big picture" of a purchase, you want to run this engine and use it operationally. You might want to limit the scope of how many cars you pull, how hard you make this work, how much maintenance and cleaning lubing are you up for? Last- all those always balance against your purchase price.
There are different aspects of this hobby and different members participate or focus differently. Again, some people are runners- operators. Some folks are light users with very occasional lightly loaded use. Some people are collectors. Then you get into skillsets. Some folks will tear down an engine right out the box. Some people are scared to remove 4 screws to take off the shell. Some people can't solder if their life depended on it. Some people do component level repairs and reverse engineering of circuit boards. These all combine into- are you a repair type person and do your own maintenance and repairs, or are you the type who has to pay someone? And, then, do you have someone familiar with this engine and it's quirks, parts availability and so forth?