Interesting. So the one from JR is outdated (Trainz 2.9) ironically and the one I have installed from the DLS is for Trainz 3.6. Even more interesting is that both are made by lilb. So they are indeed the same. I had originally thought to ask here as I did not want to mess up the GS-4 addon I already had installed in case it would overwrite it or something like that. Thankfully it did not overwrite it or corrupt the one from the DLS. So all is well and answered.
They are two different models of the same locomotive by the same author.
With Trainz, the build number, i.e. 2.9, 3.6, 4.6, etc., while isn't what you are looking for in this instance. What you need is the KUID number. Since the KUID numbers are different, they are considered two different models even if they are the same locomotive. This a very unique thing to Trainz and very helpful, and very important. The KUID and the KUID2, and updated KUID system, was developed in the earliest days of Trainz. The developers thought it was important that having a unique ID system for each asset be implemented.
A KUID is made up of 2 parts - the author's unique ID : Asset ID number. My UID is 124863. Any asset I have will be <kuid:124863:xxxxxxxx> where the xxxxxxxx equals some asset number.
The reason why this is important is it allows many SP GS-4 steam locomotives by the same author, or many authors without having one overwrite the other asset. This has its advantages and disadvantages as you'll find out later while route and session building.
The KUID system was built without versioning in mind. In the early days, an asset was obsoleted by manually updating the obsolete-table found in the asset config.txt file. While this works, it's cumbersome and prone to mistakes as many of us have found out the hard way on many an occasion. Since this is a manual edit, a simple typographical error can turn a working asset into something else, or render something else faulty or many other assets faulty if they rely on this particular asset is missing due to that single typo.
To get around this, the developers created the KUID:2 system. This works similarly, however, it allows for an asset version.
<kuid2:124863:xxxxxxxx:1> is the original asset in this system. <kuid2:124863:xxxxxxxx:10> would be the 10th revision of the same asset. With this system, we can have 126, possible versions of an asset. These versions will obsolete the previous version of the assets automatically without needing to manually editing any config.txt files.
I hope this helps explain the ins and outs of the kuid system, which will help you understand the versions of assets that you'll be installing into your Trainz program.
