British Thornton Ad050 Log-log Slide Rule, Boxed, Good Condition British Thornton AD050 Log-Log Slide Rule, Boxed, Good Condition. In original slip case. Please study all pictures for your own impressions? We will always combine postage but please contact me first for a quote. I ship via Royal Mail, DHL,USP, post-priority service that takes 1 week within European countries and 1-2 weeks to the other countries.. Proof of postage & tracking number always will be provided.