Rattle in 2nd-4th, now additional separate 'rattle' in neutral-5th + reverse

Hey guys

So as per title. Jimny 2007 JLX

I think the gearbox bearings need replacing / whole new gearbox; but also unsure if there is an additional issue.

There was a rattle in 2nd gear - 4th gear, suggesting bearings. This would stop if in neutral (coasting), 5th, or reverse.

Gear box oil is fine (checked by mechanic). O-ring on front prop shaft replaced as per:  www.bigjimny.com/mediawiki/index.php/Gea...put_end_oil_leak_fix

In addition to the bearing rattling there is now there is a much louder, deeper, 'rattle' (more like playing card in spokes of bike type sound) when moving at all whether neutral (coasting) right through from 1st-5th reverse. The car slows down considerably while in gear as if there is a resistance. 

No noticeable smells.

Looks like oil leak around engine too? I'm not paticularly clued up on the mechanical side of things!

Added are some photos and videos.

Any advice and suggestions welcome!
Thanks

Gearbox to front prop before o-ring replacement 1


Gearbox to front prop before o-ring replacement 2
 

Engine top


Engine oil colour


Video of rattle (most noticeable in 5th gear)
youtube.com/shorts/-VBVvFopoJU?feature=share

The noise appears to be dependent on road speed. I'd be more inclined to suspect the transfer box or axle. Do you get the noise in low range?
Take it for a bit of a run then stop and feel the gearbox, transfer box, diff and each end of the rear axle. If you are getting enough friction to slow the car down, something will probably be getting pretty hot. If nothing seems that hot, check the front as well.

It is also worth checking the oil in the transfer box and diffs. Generally by the time a gearbox, transfer box or diff gets that noisy you start seeing shiny particles in the oil and get lots of shavings stuck to the drain plug.