I very much doubt if the Hillier tape is still available. a place to try is www.dancesport international.com The above mentioned are the people who run the letter service plus the letter service on video. Somewhere I have their catalogue which they send to me from time to time. If I find it and there is more information I will put it up.If you can find a copy I would recomend the John Woods Anne Lewis video
on Waltz and Foxtrot.Most of the more recent videos get straight into variations Both of the above mentioned give masses of technique. I suppose they give the public what they want and not what they need. You might also try Qusar Video Productions also in the UK.Happy hunting