How to centre a panel in an aperture - a Victorian cheat!

I removed a window from an Aberdeen property this week which had a feature I've not seen before. The external lead leaves on the vertical sides of the panel had been shaved away, and an additional 1/2" lead leaf had been tack soldered in place.

Initially I thought the soldered on lead leaf may have been to disguise the ill-fitting panel, but actually I think it may be also offer a very clever solution to a problem that often occurs when fitting panel in a frame with larger rebates.

Ideally there will be 1-2 mm of lead showing above the mouldings or rebate on a timber front door/window. This finishes off the window against the rebate nicely, and allows a lap of paint over the putty or bead onto the lead if required. However, it is not always possible if the rebate is wider than the external lead. Because of the allowances left when fitting a window, it can be difficult to get the lower horizontal lead came to show above the lower horizontal moulding, as the window sits hard against the lower edge of the rebate.

By adding an extra flange of lead, the panel is made to appear centred in the aperture, even when the border came is narrower than the mouldings and rebate.

In the foreground of the image below is the ​base border lead, pinched closed, and capped with a 1/2" lead leaf tack soldered and overlapping onto the lead. This leaf has been added closer to the glass, so that when the 15mm moulding is in place some lead is still visible.  The right hand lead in the image is comprised entirely of a tacked-on leaf of 1/2" lead, while the actual border came underneath has been shaved down to the heart.

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I can imagine a couple of scenarios when this technique may come in handy.​

1. When the mouldings are 18-20mm deep, hiding 12mm border ​came. When rebates are deeper than this, we usually install a hidden row of border bricking to ensure the moulding grips lead, but for a small discrepancy this would work fine.
2. When a panel has been made too small, necessitating the removal of the outer lead flange during installation, the effective depth of the rebate and mouldings is increased. By tacking on a leaf inboard of the edge of the came, the lead can be made to appear above the rebate again. One other advantage of the technique is that ​it can be carried out on site if required.