Is the CD component across the secondary? I would unsolder one side of it
and determine what the value is. If it is across the secondayr, it is
likely an oil filled high voltage cap.

The tape is likely to prevent a mechanical resonance. However, examine it
carefully. If the screws are insulated, it could be to correct a short to
case, which could make the case hot.

There is a lot of information on DX-100 rigs on the internet. They sounded
good before people started converting them. Electrolytics may need
replacement, but it shouldc be a smooth operation to put back on the air.

73, Colin K7FM