HP-71B Changing Lower and Upper Halves

[MikeSD]

I'm wondering if there are compatibility issues when changing a lower or upper half, on an HP-71B.

I'm not talking about going from metal to plastic back. But I have seen a couple versions of the plastic backs. There are at least 2 versions of the zebra strip connector pad arrangements. Very minor board layout change. But it made me wonder if top half must be paired to a specific lower half, or if if any plastic back lower can be used with any plastic back upper. Anyone know?

I tried hard wiring between the zebra connector pads on an intermittent connection but it wouldn't work at all.The flex cable on metal back is easy to bypass. Anyone have a good tip for bypassing the zebra strips? I just wired straight across. Seems pretty straight forward.

There is an unused pad near center that I just skipped.