Replacement greenhouse parts

Good evening people, I was wondering if I could pick some brains... I was recently given a second hand greenhouse, I disassembled it myself and transported it myself, however having gone to reassemble it today, I have noticed I am missing a 6ft base plate and a 6ft gutter section. I have spoken to the person who gave me the the greenhouse and its not there, I've also treble checked what I have and it isn't present. Does anyone know of a company that sells replacements, unfortunately it's an old aluminium structure that was at the house when my friend bought it so we don't know the manufacturer, but I would assume they're pretty generic? I'm a welder by trade, I could fabricate the base plate if necessary, but the gutter section is a different story.

Thanks in advance.