For the sake of image sharpnes, you will want to expose with the emulsion coated side facing the lens. The paper carrier, regardless of how thin, will diffuse the image, while causing at least some light loss.
Use regular paper developer to process the stuff at first. This will allow you to figure the effective speed you are intersted in when the H-D response comes off the toe. For now you really don't care about how dark the highlights become in the negative.
I started my calibration efforts by photographing a set of black to white reflective squaures on a page in an old Kodak B&W Darkroom Dataguide. The neg would be looked at to see what exposure showed a difference in printable denisty betwen the almost balck and fuly black tile, when metering for the neutral grey card that was in the dataguide on the opposite page from the different grey steps.
The next step, when I went to 4x5 was to stick a kodak print projection scale in front of the film in the film holder, and meter and set the shutter for neutral grey.
Then I was given a densitometer, and sprang cash to buy a 120 sized 31 step step wedge from Stouffer. That was money that was well spent.
Consider a low contrast developer when trying for pictiorial response. If it is orthochromatic you should be able to develop by inspection until you get a development time dialled in.
For low contrast I have heard of people using selectol soft at 1:10.
Ansco 130 at 1:10 with some extra retainer to conquer fog was alos recommended to print lith film for continuous tone response.
I am about to calibrate some x-ray film in a similar way, and I know it is a high contrast product.