sorry to hear about your neighbour, they all have some value, how much couldn't really be determined without photographs.
from your description i'm assuming they are unregistered, to be sold they will need to be "identified" and registered. the process might be different in QLD, but in nsw they need to go to a gunsmith/dealer? to be identified, then from this they will be registered in someones name or possibly in the name of someones estate. i have heard prices for identification ranging from $30 to over $200, so it would pay to shop around.
the sporters, as parts guns would range from a minimum of $150 ea up, if they are in reasonable condition, being early lithgow rifles (desireable) probably a fair bit more. the full wood lithgow probably a minimum of $400, the 1902 bsa??? probably use the minimums for the lithgows, though being a 1902 it wasn't build as a no1 mk3, this could increase it's value as parts or a shooter/collector.
the peep sight on it's own, if complete, would be worth a minimum of $100.
the 1918 with scope has me intrigued, the chances are very slim that it is a sporterised genuine sniper rifle. but on the off chance, it would be worth finding out for sure as genuine snipers are in a whole other league all together $$$.
https://www.usedguns.com.au/ probably has the largest turnover of rifles in Australia, i think some of the lee enfield prices are a bit higher than you can find at your local country gun shop, but it will give you an idea.