Some time ago I mentioned a large book entitled "Istanbul Steamers"
I have now got a copy and, sorry PJ, there is no mention of the former DIANA VERNON/WORTHING BELLE.
There are a lot of paddle steamer photos, of steamers at Istanbul not owned by Sirket-i Hayriye, which were the subject of the previous "Bosphorus Steamers" which is in a similar formet. Ships mentoned have a colour profiles for each ship of class of ships and there are odd plans here and there