A230 Linkage Up or Down?

flipping the levers will just change the location of the gear positions on the stick; it should have no bearing on the shifting. Reverse should be to the left and up IIRC
If you have hydraulic system, then ignore all #4s
Do not use any synthetic period! In winter you can use 100% ATF.
The Hydro TO kit eliminates all external problems
I can tell you exactly what the problem is , but don't hate me...... the brass is not locking onto the brake-cones.
They could be worn out, or they could be oval, or it could be that the oil is too slippery, or the clutch disc is dragging, or the engine rpm is hanging up,etc..
Once the rpm is severely mismatched, as in the engine went back to idle while you struggled with the shift, those dinky brass rings can hardly drag things back into synchronization,when they are working correctly;.....never mind when they're not.

On the bench,gear in one hand and brass in the other,and both fully de-oiled; the brass should begin braking on the cones with the tiniest of pressure, and kindof screw themselves on until it all locks up. At this point, there should be close to or better than .050 distance remaining between the brass and the main body.
When working with used brass, I put the best-locking, and highest-sitting one on second;gear, the worst on direct.
(I'm guessing at the .050 spec, cuz I've never actually measured it. I'm guessing a cold measurement of maybe .020 would be too small. The brass will expand when hot and hit the main-body before any braking would occur. But even if the number is big enough to brake on day-one, how many miles before you're ripping it apart again. So the higher the better. I don't think I've ever seen one higher than guessing, .080 )
If you can't get a good lock, you will have to put the gear on the lathe, and with 120/150grit emery cloth stretched over a long file, rough up the cone, using a stroking motion, as if you were actually filing it. You will probably find a little ridge on the bottom of the cone up next to the main body; this has to come off. Do not take material off the rest of the cone; just take the shine off. Don't spin it too fast, a couple of hundred rpm is lots.
If the brass rocks on the thus polished cone, it is oval, and will never work properly. If you are clever, you will figure out how to make it round again, and if you can get it to brake properly, congratulations. Just don't put it on second gear.
Make sure your engine is returning to idle properly, ie the throttle blades are snapping closed.