Never heard of any Tandons in Nepalese history before, LOL
Bro please read your history again. go and read kot parbha and then bhandar khal parva and then Nepal tibet war. you will find him
cha ghar thar it's isn't char jaat please again check your refrences.
Aviman singh Rana was the rana magar the first high ranking officer to be shot in kot parbha.
Thakuri wasn't even there until after Junga bahadur got himself lal mohar that he was a rajput Rana. then to seperate themself from chhetri they became thakuri and all those kings before nepal was unified were shown as Thakuri e.g Sen ( wait you might say there were no Sen too in Nepalese history)
Chhetri weren't allowed to go in to British gorkha. the only times you will find them for fighting for british is when jung bahadur himself went to india to stop the india revolution in 1857-8 that too under his command.
Then in 1914 and again in 1938 during two world wars.
why don't you read a column in sukhrabar published by nagarik news every week you will find lot of things about nepalese history being corrected.