Replace your trailer lights with newer and brighter LED tail lights that are more reliable and more visible. Right side is curbside light. These lights match the more square style lights on newer 26M trailers but will fit properly as a replacement on any MacGregor Trailer.
This screw-in style 2 pin connector should be more secure than the factory 2 pin. The mounting holes will not line up perfectly but should line up enough to make it work, or just secure it to the deck with some good marine sealant.