Regarding the low E/Eb issue, if there is not a fifth key for the low Eb, then you have a low E horn. While the Albert system does not have the same degree of duplication as does the Boehm, there will still be two keys for the LH little finger and two for the RH little finger on a low E horn, and an extra key (I've only seen it on the RH side) for the low Eb. (There is also a mechanism whereby the C# key operates a cross-connection that helps with the LH/RH switch issues (the same reason that the rollers are there) when dealing with fingering problems. I forget the name for it and don't have any of my reference books handy right now, but someone will fill this in for you, never fear.) Regarding the cleaning, the approach that I took was using the naphtha lighter fluid on a rag to clean off the crud accumulation (including key oil leakage onto the joints, the big crud collection source in my opinion). (I swear by Ronsinol over all of the others - less smell, better containers (take a sharp knife and trim off the little blue tab in front of the folded spout), and better stripping action than the others. We probably have gone through thirty containers of it over the years, all without lighting a single cigarette. They probably wonder what it going on up at FBI headquarters.) Then, after judicious application of the penetrating oil to reluctant screws, I disassembled the key work, using a labeled ice cube tray for the small parts, stripping the horn down as far as practical. Following that, I stripped the cork attachment points and cleaned them off of the remains of the adhesive (with mild applications of heat to help), then thoroughly oiled the joint with bore oil, threading oil soaked rags through the bore and tone holes. After that sat for a week or so, I stripped the excess oil from the joints, bagged (in labeled bags) the key work up (after first heating and removing the shellaced pads from the key cups) and hauled it off to the repair place for final setup and re-padding. I didn't remove any springs (of the needle type) and only removed, cleaned and replaced the few flat springs on the instrument. When I got it back a week later, the only additional step that I took was to press gold leaf into the maker's stamp. Had I owned it, I would have put the extra money into having the dented up bell and neck into original condition (I have had this done on other old instruments in the past but 'then future') and having them both re-plated (along with the key work) in silver. Expensive, but if you are allergic to copper like I am, well worth the price.