Understanding Society User Support

I am trying to continue analyses I have carried out with the 18 waves of BHPS with the inclusion of the BHPS incorporation sample in US w2. A key variable is urbanity. The urban/rural variable for all bhps (England and Wales) URINDEW is availble under conditional access (SN 6032) rather than being in the main release, whereas there is a variable available directly in the US main release 6614, b_urindew_dv. So, I want to extend analyses of outcomes in relation to urbanity using the bhps incorporation cases in SN 6614. The problem: the variable b_urindew_dv is coded differently from the bhps variable urindew. Urindew is comprised of 8 categories: 1 and 5 are urban (>=50% of LSOA population in settlement of >=10,000, 1 with sparsely populated surrounding area and 5 less sparsely populated); 2 and 6 are town and fringe; 3 and 7 village; 4 and 8 hamlet - again distinguished by nature of surrounding area. BUT!!! b_urindew_dv is coded 1=urban and 2=rural - I guess, though this is not made clear, that 1 and 5 are collapsed to urban, and 2-4,6-8 are collapsed to rural. It is clear from the codebook that the intention is to code the variable exactly as it is coded for bhps, see https://www.understandingsociety.ac.uk/documentation/mainstage/dataset-documentation/wave/1/datafile/a_indresp/variable/a_urindew_dv but this has not been done for wave one either, as a_urindew_dv is also binary. It appears that the data depositor has deposited the variable in a collapsed form, contra the codebook. I need the 8 part coding for my work - I need to distinguish 1/5 from 3/4/7/8 and remove the cases that are neither strongly urban nor strongly rural. Please advise me. Thanks in advance.