I have a problem with the REO Grand I just got, and while I should probably post this in the REO section, I figure I'd post it here because I want to fix it myself and all my favorite favorite electrical gurus are here already

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So here's the background. I got this REO Grand in trade. It's in decent shape, except completely loaded with what I guess to be Pluid (STRONG minty licorice flavor/smell). I cleaned it out with 99% alcohol, and it seemed to be working OK... but I'm noticing extremely fast battery drain (like going through a full 18650 battery in less than an hour), which makes no sense, since my woodvils run all day without a problem vaping roughly the same thing, same atomizers, etc.
Today, it stops firing consistently, so I took a look inside. Notice that when the firing pin actually connects, it's SPARKING. Pretty, bright yellow fire sparks, flying off the top of the battery every time the button is pushed down. Hrm. Short? Well where the heck could it be shorting? So I take the one center screw out, remove the plastic cap thing, and look at the metal tongue thing and it's ok, the silicone sleeve it's in is OK ... I see absolutely nowhere a short could be occurring. It's not my atomizer, I have 3, including the RM2 it came with, and all 3 fire fine in my Woodvils, and all 3 do the same thing in the REO Grand. It's not the atomizer.
Well, I wiggle everything around, reseat it all, add Ox-Gard (don't have De-oxit) to the point, and now it won't fire my flat top batteries it was working with... but is working fine with button tops. This tells me the metal tongue wasn't fully pushed to the top like it should have been originally, since the tongue does not protrude lower than the plastic when pushed all the way to the top. I can also see now that this is what forces you to use a button top battery- the button fits inside the screw in plastic attachment. This plastic pinches the tongue upwards in the center so it can't depress down enough to fire a flat top without being slightly detached on the bottle side. So my REO is fixed, but I don't like it fixed, because I want to use my flat top batteries.
So, if the above makes sense, any suggestions for what else to check would be appreciated

. It's not sparking anymore (with the button top, and the tongue pushed all the way to the top), but why would the tongue being dropped a bit lower cause it in the first place?
I started wondering, with all this talk about BeCu connections, whether it would be practical to improve the connection by attaching a very small BeCu strip to the pointy tip of that depressable tongue. If I can get my hands on a silver plated BeCu strip, and epoxied a very thin strip to the very tip, it would drop the contact point lower, allowing me to use a flat topped battery...
So here's the question, would using epoxy on the end of the strip, while the other end of the strip is simply physically touching the original tongue sufficient contact? Maybe with a layer of ox-gard inbetween the 2 metals? Would solder be better? Would it make a difference in connectivity, when the entire strip is not BeCu, only the tip?
Why shouldn't I use a flat top battery in the Reo Grand? Was there a good reason for being forced to use buttons in the first place?
Thanks

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