I am going to assume that the plate is the thin line on an angle at the end of the expanded beam which goes from left to right in your illustration. Assuming that, your geometry look good for a reflection hologram.
If the distance from the film to your object and back to the film is longer then the coherence length of the laser, the light that goes through the plate and hits the object and bounces back to the plate will not help in making the hologram. This alone without the other "helper" object lighting would be a Single Beam Reflection hologram. But even if the object is to far away for your coherence length, you should still be able to use the "helper" light to get the beam paths equal. You have to start measuring from the beam splitter down the reference beam path to the plate. A non stretchy string works great. Then you have to insure the "helper" object lighting is exactly the same length (or actually within your coherence length). This needs to be measured from beam splitter, down the path to the object then from the object to the film. I would get them within a 1/4 inch or so.
As a first test I would drop out the bottom object lighting (or just block it out) and take the object and place it as close to the film as you can (almost touching) and try to make that hologram. You can then insure that your processing is correct, then go back to the additional object lighting if you wish. Stability is a must for reflection with a free standing object. My suggestion has always been to make a hologram with the plate lying right on the object for a first attempt. That way there is minimal leeway for movement. This illustration uses film clamped between two glass plates which could be a holographic plate alone and the illustrion uses supports for the object but I would suggest using an object that lays steady on its back and a plates will lay steady on the front.
http://www.holograms3d.com/Illustration ... Single.jpg
For this configuration, you can either mount your laser overhead and point it down or point it up to an overhead mirror and then stear it down to the plate. This is just a suggestion to elliminate movement as your problem in which you can then concentration on processing. It's hard to find a problem when more then one exist. You don't know if what your changing is good or bad.
The brown rings that you see in processing probably match up exactly with the Newton rings you see from the specs on your lens. Place a white card where the film would go and look a the the laser light expanded through the lense hitting the plate. Do you see the same rings? While a little detractive from a final hologram, you should still be able to get a hologram despite these rings.
Questions/suggestions:
Do you bleach until the plate is clear?
Are you using plates or flexible film?
Do not dry the hologram at all with hair dryer, let it dry naturally after squeegying the water off.
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