battery tray rust repair - firewall metal shaping?

[ol doc gully]

I am repairing rust under battery tray. Going to do the firewall piece first but can't figure out what the best way is to get a piece to match with the stamped / bead roll shape?

 

If you look at the picture of the area you can see the line of approx where I need to cut to replace rusted bits (approx, will keep grinding to confirm). I definitely do not want or need to cut up high enough to be above all of the stamped shapes, so regardless of exactly where I cut I need to figure out how to fit these shapes.

 

The drawing is my best stab at how I might go about fitting a piece to match those shapes; basically leave some tabs that I can bend over and weld to the recessed portion. But its not going to look very good because in multiple areas (ie, sides and bottom) it will have to line back up with the recessed part of the firewall. Or I could try to hammer those areas flat where they meet the panel I am welding in, but that seems even less desirable.

 

What has anybody else done?? 

 

EDIT: Thinking about it more now after re-reading this posting; strength-wise, I think having something that is completely in plane with the recessed portions is likely the preferred solution....

 

EDIT EDIT: I suppose I could do the reverse of what I have drawn; weld to the recessed panel and leave tabs to be bent back *out* to fill in gaps at bottom of the stamped shapes. But that seems... difficult

 

Edited May 14, 2020 by ol doc gully

[Neverdone]

Wouldn't it be much easier to spend 90 dollars on a bead rolling tool (i.e. https://www.eastwood.com/eastwood-elite-8-heavy-duty-bead-roller.html) and then just remake the whole thing and weld that in?

[grannyknot]

Or, since it is all hidden behind the battery anyway, flatten the bottom edge of the stamped section where you made the cut and just weld it up to your new patch.

[ol doc gully]

5 hours ago, Neverdone said:

Wouldn't it be much easier to spend 90 dollars on a bead rolling tool (i.e. https://www.eastwood.com/eastwood-elite-8-heavy-duty-bead-roller.html) and then just remake the whole thing and weld that in?

 

Cutting out the whole thing adds a lot of complication (up high on the other side of the firewall, etc), this is not a bare chassis restoration. However, that is a much better deal on a bead roller than I would have expected, may be worth getting regardless...

 

21 minutes ago, grannyknot said:

Or, since it is all hidden behind the battery anyway, flatten the bottom edge of the stamped section where you made the cut and just weld it up to your new patch.

 

I'm curious if the panel will start to bow or anything by increasing the width but I think that is workable, I may go this way.

 

Thank you both for your input.

[LLave]

There is a company that makes a reproduction Auto Panel Solutions, I see their stuff on facebook. 

[silverado22c]

battery-tray-area-patch

 

This is at skillard.com for $120.