The construction of this nominal liquid assets series was quite complicated, as a result of changes in the coverage of the ONS data bank. To recreate the series AMFX, RRGY and ACUV, a backcasting technique was used. ULC and UMC are normalised to equal 1.0 in 1990. Note that the ONS variables have the suffix QU for quarterly unadjusted. This gives annual observations for the United States, 1860-1988.
All series are in logs except bnd.
You should examine the file readme.ukm at this site for more details.