150 Yamaha Data info

[Fountaine]

I am having a problem figuring out the date info. The plate is damaged and I could use some help:
The Model is a 1, I or T 50TXRT, it is a 150 hp so I guess a 1.
The prefix is 6G4.
The next is J, O or UL .
The serial is 761083 Y

Please help with all you can, Thanks.