"Simpson & Co. Ltd.*is a Chennai,*India*based manufacturer of agricultural engines, and is a unit of the*Amalgamations Group. Simpson supplies its*Perkins-licensed/based engines to its sister company,*TAFE, manufacturer of TAFE and*Massey Ferguson*tractors.
Simpson & Co. began in 1840, and moved into engine production in 1955 when it licensed Perkins engines. Simpsons has two manufacturing facilities - at Anna Salai and Sembiam, Chennai.[1]"
Here's an excerpt from tractors.fandom.com. Perkins engines are obviously a gold standard brand name and I'd be curious of the interchangeably of parts. If they are at least based on Perkins designs then that speaks favorably to the design VS something unproven on their own.