I have just read several articles on the net that say poly coat is much more durable than bluing. Next to parkerizing polycoat seems to be the most durable.
There seems many differences of opinion as to the value of silicone spray on the innards, but no differentiation between lined or unlined.
Perhaps this is the most I will be able to obtain. I think I am just going to use silicone wipes on the guns, let it dry and then hope for the best.
Thanks for your interest.