[QLD] Do Windscreen wiper scratches and roadworthy go together ok??

Doubtful.
Have you changed the wipers?

 

In Qld, any windscreen scratch in the drivers view is a fail.

 

I tried to find it and could only buy it online.

 

New screen is the most sensible solution.

 

I thought a couple of hundred dollars was a very low cost particularly from a safety aspect.
Messing about trying to get stuff that probably won't fix your scratches, then spending hours and hours hoping they will go.....Not worth messing about for a couple of hundred.
When you have had the screen replaced.....NEW WIPER BLADES PLEASE.

 

Cheapest fix is probably a new windscreen...

 

Windscreens have limited shelf life regardless. After a number of years they breakdown and become hard to see through with sun glare. The other issue is they get sandblasted after a number of years. The etching acid you mentioned requires a mechanical buff to make it work. If you have the buff you might get the scratches out but if they are fairly bad you could be throwing money at a problem that the acid won't be affective anyway. Like I said only place I could buy it from was online.
Buying the chemical from a Jeweller is like going to a bakery and asking them if you could buy some flour. They may or may not sell it too you, chances are they will say no. But like buying flour from a baker out of 150 bakeries you might find one willing to part with some materials.

 

Shop around
$200 or less up here.

 

Novus repairs windscreen scratches, chips and cracks as well as replacing windscreens.
GT Glass does the same and they have mobile techs just like Novus.

Both the above have operators in Cains

Give either or both a call and have a chat... often it may be better to polish than replace, especially if the windscreen is rare, expensive or unavailable.

 

I was talking to somebody a couple of weeks ago (maybe longer) & he said he replaced his windscreen (vy) for $150.00 (l thought it would have been dearer). I think he mentioned Windscreen o'briens. Maybe wrong on that?

 

^ haha, a new windscreen in the back seat won’t help the roadworthy pass

 

If the scratches are bad enough, polishing may leave low spots on the screen that can cause vision and wiping problems.

 

From my research on the product you use, if the scratches are deep enough to leave low spots the marks won't come out anyway.