It is an easy matter to thread it back again in the unlikely event that this occurs. The whole lamp spins on the base and the pedestal ring also spins on the lower base; this does not affect the stability.
I have not attempted to access the centre connecting rod to dismantle the lamp. The font is the drop-in type. The chimney is a "Bear" brand crystal and is sound but is scratched on one side. The item "Late 19th C. Antique, ceramic Hinks oil lamp No. 2958" is in sale since Wednesday, June 5, 2019. This item is in the category "Antiques\Antique Furniture\Lamps\Victorian (1837-1901)". The seller is "peterdial12" and is located in Lewes.This item can be shipped to United Kingdom, Antigua and barbuda, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Australia, United States, Canada, Brazil, Japan, New Zealand, China, Israel, Hong Kong, Norway, Indonesia, Malaysia, Mexico, Singapore, South Korea, Switzerland, Taiwan, Thailand, Bangladesh, Belize, Bermuda, Bolivia, Barbados, Brunei darussalam, Cayman islands, Dominica, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, Grenada, French guiana, Iceland, Jersey, Jordan, Cambodia, Saint kitts and nevis, Saint lucia, Liechtenstein, Sri lanka, Macao, Monaco, Maldives, Montserrat, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Turks and caicos islands, Aruba, Saudi arabia, South africa, United arab emirates, Ukraine, Chile.