1982 Siel Opera 6

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via this auction

Curios what that solar panel looking strip is on the left under the controls.  Note this one is being offered for parts due to battery damage.  Some pics of the inside below.

"The Main CPU board had battery damage and this is very common for these there were only around 2000 ever made and I see around 4 on ebay world wide per year.

The voice boards are undamaged as far as i am aware and all filter chips and DCOs are on the board. the only work on this that has been done is the CPU board. It has been stripped back to reveal the PCB underneath that does not have too much damage. Please see the pictures below."

Update: I heard back from the seller.  The strip is a paper preset sticker.