I'll probably make a fool of myself for trying to answer this so I'll start off with this disclaimer. My bike is locked in a shed 20 minutes drive from here, so I can't just look at it, and I'm not going to cheat by looking up images or specifications on the internet. I'm also very aware that not every model or variant of TY ever made came to Australia, and so there may easily have been features that were standard on some bikes that I've never seen. So here goes:
The front forks look wrong. All the ones that I know have the axle in line with the center of the forks, not offset forwards.
The front hub looks wrong, and the front brake mechanism, and the lack of a speedo cable drive point, Presumably with the different hub, the spokes in that wheel would be different too.
The front mudguard mounting brackets, and also the metal front mudguard.
The fuel tank looks wrong: wrong shape and too small.
The front of the exhaust looks wrong. I can't say for sure what it is that's wrong about it. Is it routed differently? I may just be thrown off by the different look because of the smaller fuel tank leaving it more exposed.
The bracing on the downward frame tubes immediately below the fuel tank doesn't look right to me. Is it because of the absence of the built in tool box?
The bash plate doesn't appear to be wide enough, and the hole in it at the front right corner immediately below the down tube doesn't look original.
The removal of the oil pump is evidenced by the missing oil tank (Left hand side behind / below the side cover), the missing control cable to the pump and the missing oil in and oil out tubes to the pump. The picture is a bit too dark and indistinct for me to be sure what I'm seeing. Is that a different side cover from an engine without an oil pump?
The part of the engine housing, (and I use that term loosely) which normally partly covers and protects the drive sprocket appears to be missing.
The seat appears non-standard. (this comment coming from someone whose seat is made of duct tape.
)
The loop of frame which normally extends rearwards and supports the plastic rear mudguard is removed. I know this was done on the Majestys, but I'm not aware of it coming out of Yamaha like that. The mounting bracket for the rear muffler is modified, as is obviously the mounting bracket for the non standard metal rear mudguard.
What was originally there would have been removed to facilitate the welding in of the large non-standard webbing / bracing to also facilitate the mounting of the differently positioned non-standard footpegs.
There is no folded sheet metal chain guard. These regularly vanished, but I suspect they all came out of the factory with them.
I can't work out from the picture if the rear shockies have two separate differently rated springs each, or whether they are somehow strangely wound dual rated springs, but either way I suspect they are non-standard. They also appear to be standing a touch too vertically.
There appears to be too great a distance between the lower shock absorber mounting points and the rear axle. There also appears to be too much space in front of the rear tyre. It may be an optical effect which wouldn't be noticed if the empty space was filled with the bottom half of the normally visible oil tank, the original white plastic mudguard extending much further down towards the swing arm, and the original chain guard, but I suspect that we are looking at a non-original extended swingarm.
I also agree with TerrY. I think you asked the wrong question.