Table D2.14 of NCC 2019 calls for several different slip-resistance levels, depending on the slope of the ramp and whether dry surface conditions or wet surface conditions apply. Assuming a slope between 1:20 and 1:14, and assuming the ramp will be exposed to the weather and therefore in use when wet, P4 slip resistance would be required. You will find various slip-resistant decking finishes on the net that achieve a P4 rating, including Intergrain UltraDeck, Sikkens Cetol, etc. 

To identify the species we suggest you contact Dr. Jugo Ilic in Melbourne. He is an authority on wood identification and you will find details of Dr. Ilic’s background on several internet sites including this one: http://www.woodreview.com.au/news/jugo-ilic. If you email Dr. Ilic at knowyourwood1@gmail.com he can advise you on the required sample size, fee for service, postal address etc. We doubt Dr.