Hello Gerard, There is a Heavenly Twins owners group website where you might find the answers to your questions. It can be found here: https://htcca.co.uk
According to the information we found, the HT27 was introduced in 1989. The LOA was 27 ft. Prior to that, the LOA was 26′ 2″ (26.17 ft) / 7.98 m.
Hope this helps.
