Hello and thank you for your question. I will be very pleased to assist you. I'm a practicing lawyer in England with over 10 years experience.
For the avoidance of any doubt may I clarify that this is definitely an EPA and not an LPA please?
It is definitely an EPA which was signed and dated in May 2007 i.e. it should still be valid before the law on POA's changed
on that basis, providing your father still has mental capacity, the during power of attorney does not need to be registered for you can act under the same. The enduring power of attorney will need to be registered if your father loses mental capacity
if your father still has mental capacity, from your point of view, it would be better if he signed the contract and transfer documentation rather than you as attorney. If this is something not possible for practical reasons, providing you are confident you could demonstrate that the sale of property is in your father's best interests if challenged by any third party on the point, it is in order for you to arrange to sell is property as attorney.
ideally, you would obtain written instructions from your father instructing you to sell his property as his attorney in order that you could demonstrate that you were acting in your father's best interests and upon his instructions
is there anything above I can clarify for you?
That's fine, I have a potential private buyer for his property who is about to make an offer and just wanted to know where I stood legally from the conveyancing angle. I will obtain my father's written instruction as you have suggested. Thank you for your time.