the 45 long strap is lined in leather...
i have one in Rouge H clemence with brushed gold hardware
yes, it is heavy (even for a guy like me who is used to carry birkin 40) but i have no idea how it compares to a JPG I or II
but as it is a shoulder bag, it may seem slightly lighter (compared to b40 of course)
I have come across this at resellers in Hong Kong as well as in Japan. both are sold with a premium (even as preloved) ranging from USD 15,000 to USD 20,000! yes, the premium is crazy!
IFFAH, thanks for posting the pics of the various B45! the tricolor is so wild that I can't help but LOVE
it! lol! sure would be a fun bag to carry!