Strida 3.3 Issues

Just lucked into a Strida 3.3 on craigslist and wondered if theres a procedure to check for faulty issues (such as holding steerer tube and front brake and rocking cycle for headset play)
I’m a little skeptical because it was an extremely good deal Though the person selling seemed very legit and said he acquired it as a gift, but I tend to be cautious. Any input?
Thanks in advance … 0e7a79.jpg

This is not a normal Strida 3 as the wheels have been changed to 18" like this:
[url]18" wheeled modication on Strida 3]