Need parts breakdown for very early Yamaha/Mariner 25hp

I picked up a very early 25hp motor.

It came with the lower in pieces.

I need a parts breakdown for it.

It is a
Yamaha 25A
648L 301611

It's got a lower unit extension housing and the lower separates like an old OMC unit with a horizontal seam right down the sides of the gear housing.

[boats.net]

No we don't have a parts listing on that model Yamaha.

Any suggestions?

[boats.net]

A 1991 W25M Mariner model 7025218YW has a gearcase like what you are describing but don't know if it's your motor or not.

Thanks, I'm getting much closer.

I see a lot of the parts described there as NLA

I'd really like to find this as a Yamaha.

As with another early Mariner I own I have found the Yamaha counterpart parts to be considerably cheaper and might be a bit more obtainable.