Yep, fond memories.
I have been both engineer and pilot on Islanders and Trislanders, often in some strange and out of the way places.
I am sure the Wiki list posted earlier is incomplete or inaccurate.The prototype had Continental engines. The most common aircraft are the -26 and -27 260 hp variants. Then the -20 and -21 300 hp versions, the tip tanks being the other difference.
The Trislander came in 3 flavours also, - the obvious one being the long and short nose varieties but also the FAA certified version with auto-feather.
For those that have flown the Islander and remember 65 Kts as being THE figure.... Then it it is much the same with the Trislander. Problem being you now have yet another number to memorise... 80Kts.
I have been to the factory in Bembridge but the Islander was also produced in other places about the place, - I think South America and Asia.