Dennis
The same happens to me every 3 years. As you know the person testing you has to have the same or higher licence than you.
In my case as a TRE only the authority can test. But Fred and Richard do not hold the 500 on their licence. Fred's solution he would observe a test from the back seat of a 500 ( not sure he could see much ! ) while i tested another pilot !
Set me back £ 1300 ish plus paying other pilot etc etc
Speak to Fred very accommodating