Stuck with last four, same corner
22a Majuscule 7,6 ltrs capital ???u??
17d groom at an inn 6 ltrs ???l?r
13d most concise 8 ltrs ?r?????t
18d wrest the power from 5 ltrs ?????
Thanks samiemalone and scorpiojo, all fits now. I have never heard of a tun, so looked up, once i got t from capital letter as the answer, i had put urn. Thanks again