Check with Darkroom Innovations / The View Camera Store http://www.darkroom-innovations.com/ and ask Fred about making you a "calibrated" step wedge. He did this for me a few years ago.(posted 8186 days ago)He copied a calibrated step wedge onto 4x5 TP, then read the densities with his freshly-calibrated densitometer and noted them. It was around $30 or so compared to double or more that.
I know that errors could creep in by doing it this way, but it's far better than nothing and probably better than an uncalibrated step wedge.
Otoh, if you could get ahold of a step wedge perhaps you could get the people at your local photo lab to read and note the densities for you.
No idea about the reflection mode; although I have the proper placque I've never had the urge to get into that.