JVC VCR parts missing their places

Hello!

I picked up a tossed JVC HR-D540E VCR. Yes, both the brass pins and the white plastic linkage pins fallen off from the roller guide assemblies. After replacing them, the VCR seems to be working fine. But, there were a few more parts lying on the bottom of the device, and I haven't find places where they should go. Does anyone know?

- A black plastic pin ("double-sided" non-symmetric)

- A spring, about 4mm long and 2,5mm diameter

- A plastic insulating piece

Here are some additional pictures of the device, if they help...

Front/top:

Top:

Mech:

Bottom:

Thanks in advance.

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