I Believe I know which thorp you are talking about. I was looking at the same one but I ended up deciding not to go with it as its far from me.I'll respond because I just looked at an original plans circa 1969 T18. I'm 5'9" with 30" inseam. The plane felt like it was made for me. I had to dunk my head to slide the canopy closed after that it was perfect. Like rv7charlie said a lot depends on where your dimensions are. I will say the width is similar to the old 150 I fly. If you are wider, like me, you'll be cramped or alone. I didn't pay a lot of attention to the seat cushion and pedal positions, possible to get a bit of length there.
I didn't get to fly it, bad weather, but I'm seriously considering the purchase anyways.