Do you have a soldering iron? I don't think the right angle adaptor is a good solution, so I would chop off the RCAs and reterminate them with something better. I personally like the Eichmann Bullet Plugs, as they sound great and are easy to solder.
If you can't do this, it's possible that you can find someone who will. If you replace them there will be an immediate benefit, and you will be set up for the Rega.
I realize that I have also responded to a question you asked about replacing your Sansui amp. I suggested that such a move was a sideways one. Are you actually in a position to get the Rega now?
Regards,
Metralla