Hi and welcome. Some call any Indian engine a Listeroid Personally I group the engines into three basic categories and have names for all of them.
A- There are close copies of the CS that some like me refer to as "clones" .
B- Then there are the most common type of engine which are modified/simplified versions that are dislike the originals in more ways than they are like. These are most usually called Listeroids by all including me.
C - Then you have engines that share nothing with a CS other than they are diesel and have two flywheels. Big bores, long strokes, direct injected etc etc etc. I call these bastards myself
to most others they are Listeroids.
The order listed above is my preference for parts availability, current and long term. Parts for a standard CS type or clone should be available for a very long time. The more modifications or changes that are on a particular engine the more susceptible it is to future parts issues. be it supply OR getting across to the supplier the exact parts you need.
As stated parts availability varies with where you are located. Currently in the states it is easy to obtain parts for a clone or most Listeroids. Parts for the bastards are available if you buy it from the right place (Gary at Diesel Electric)