Thanks for the response ironbutt. From your response I gather that either headblock assembly should work fine assuming the headblock is in good working order. I will follow your recommended cleaning procedure.
I looked into the DeOxit 5 and found two types:
1. 'DeoxIT? D5 Spray, 5% solution, flushing action'
2. 'DeoxIT? DN5 Spray, 5%, 163 g, nonflammable, quick dry - non drip and safe on plastics'.
Is one a better choice over the other?
I checked on the web links you mentioned to better understand what to look for on the heads. Is this the web link?
JFR Magnetics
http://jrfmagnetics.com/