H GUYS- Just a follow on to original post: I looked at a number of Helio and thanks to all those who responded and also answered question and freely gave info and advice.
I finally wound up purchasing the two Helios HT 295#1709 and H800 H-22 from Pima County sheriff's Department in Tucson. Both aircraft have served well for several years at high availablity and reliability as aerial observation /camera platforms for the Sheriff's Department in Tucson, Arizona.
They were both converted to the Allison (R/R) 250 B17C turboprop engine. My intention in the short term is to continue to operate H-22 with the Turbine as long as feasible and then convert back to H700 configuation. HT-295 #1709 is planned to get back into certified configuation with a GO-480 and maybe go to Amphib Floats. Thanks to you all for your interest, help and support- this is a great forum- let's keep it up/ Cheers/ Bob Wallace
p.s- Interesting for me: My father, John E. Wallace worked for Wiggins Airways, Canton, Mass, in 1948-49. He was in the crew which Otto Koppen hired to convert the Piper Vagabond into the "Proof of Concept" Helioplane #!. Later in 1952 he worked for Helio directly and build the first 6 Helio Couriers at Canton and continued with Helio until his death in 1972. Now, by chance, I am concluding that this H-22 which I have acquired is absolutely the Last Helio (so far).