I don't know if the original Hindu system read from most significant left digit first, but if it did then the historical transmission into Europe may have entailed two flips of numeric endianness.
> I don't know if the original Hindu system read from most significant left digit first
The Sanskrit language (exemplifying the "Hindu system") had the same pattern as English for the teens, i.e:
11: ekadaśa = eka (1) + daśa (10)
12: dvadaśa = dva (2) + daśa (10)
13: tridaśa = tri (3) + daśa (10)
etc ..
In Sanskrit this pattern (least significant non-zero digit spoken first) continues through to larger numbers.
so:
20: vimśati
21: ekavimśati
120: vimśati-śatam
1121: ekavimśati-śatam-sahasra
etc.
But it's important to remember that the spoken rendering of numbers in all these languages precedes the written representation by millenia. People have been counting much longer than they have been writing. Of course later ways of speaking the numbers may have been influenced by writing systems, but the spoken rendering of basic smaller numbers tend to be relatively stable over time.
This is incorrect. They originated in the LTR writing systems of India, which is why the full name is Hindu-Arabic Numeral System.
https://en.m.wikipedia.org/wiki/Arabic_numerals
If you read Arabic, this is clear because the numbers are written in the opposite direction as the words.
> they were written and read starting from the least significant digit on the right.
Only the ones and tens place are read from the right - which many languages do, including English in the 'teens' words:
thir-teen == three and ten
four-teen == four and ten
fif-teen == five and ten
In modern Arabic, the hundreds and above are read left to right.
For example:
42: ithnaan (2) wa (and) 'arba3an (40)
142: maa'a (100) wa (and) ithnaan (2) wa (and) 'arba3an (40)