I guess you will know if your spring drops on the mod or your button melts if nothing else.
Besides all that you may have arching on the older contacts and pits on the tops of your battery from it.. you'll know you have that issue if your spinning your battery to get it to fire.
The lower you go the more it will arch.
New gold contacts,spring and button that won't melt in the kit is prob where ya wana go.. I hear people going around .2 -.3 ohms.
To upgrade that reo to the new sub ohm kit is like $25.. best to just send it in for the master to swap them out as it can be a pain.. easier if one had the newer ss adjustable 510 connection.
I'd advise upgrading that at the same time.. though after all that your talking prob around $50+.. though you should ask.
Whatecer ya do.. upgrade the contact or just order a new reo.. you would want to also get new button top
batteries.. aw 1600mah or the 2200mah.. though I hear the 1600s are higher amp rated.
You don't want to mess up brand new contacts with pitted batteries as it will arch and screw up the new gold contacts.. you want perfect new gold contacts with new butter smooth button top batteries for a perfect free of arching contact that will last.. as long as you use deoxit gold on the gold contacts.