Had a good look at it today, need to think about this one, otherwise it may turn into a money pit.
So far...
The wheels are badly pitted and could do with replacing, both tyres are perished, saddle needs replacing, pedals need replacing, brake blocks are perished.
So it's quickly adding up.
I'll probably get linched for this next comment ;-) . The twenty I have has 20 X 1 3/8 tyres/wheels, I just so happen to have a bmx doing nothing in the shed, would the 20 X 1.75 wheels fit? The only thing is they are mag wheels.