On evaluation of the rebuilder site, I am impressed with the lack of scientific and clinical evidence and references proving that the rebuilder is
effectiveEffective strength cough syrup
So, even though it may be effective in some people, there is no gaurantee that it will be effective for you. The placebo effect associated with the device cannot be evaluated without proper clinical trials. Neuromuscular stimulation has been shown to be somewhat effective in stroke patients with paralyzed or weak limbs to hasten rehabilitation, but has not been proven effective for peripheral neuropathy.
Alhtough I cannot give you a clinical diagnosis over the internet, you describe what we term a 'distal sensory polyneuropathy'. We are very familiar in the US with these symptoms - the list of causes is quite long
Initial testing includes glucose and B12 as you have had done but also, RPR (for syphilis), protein electrophoresis (for antobody mediated neuropathies), ANA and ESR (for inflammatory neuropathies)
Further testing includes tests for heavy metals, Hepatitis, Lyme disease, porphyrias, and HIV.
Various new antibody tests can be done such as anti-MAG antibody which should only be ordered by a specialist familiar with them.
A lumbar puncture to analyse the CSF can be useful to evaluate for an immune mediated polyneuropathy (CIDP)
Amyloid disease can also cause these symptoms and can be evaluated for by a skin or rectal biopsy
New information recently published shows that even people with normal blood sugars may have glucose 'intolerance' sufficient enough to cause a sensory small fiber neuropathy