Always nice to see additional development, even if it means more fragmentation.  I'll probably pick and chose from 3.1.4 components (once released) to add to my existing 3.9 systems.  Of course I don't expect anyone to support these hacked together kludges beyond myself. 

Not really fragmentation. Let me explain:

All 3.1.4 components are way beyond in fixes and features than what 3.9 brought to the table. What 3.1.4 lacks is all those third party applications that 3.9 brought along, like video player, web browser, dock bar, tcp-ip stack, etc.

The core of the Operating System is way better in all aspects than what 3.9 ever was/is.

The best part of this, is that taking some precautions, you can integrate 3.1.4 in a working 3.9 system, and get the best things of both worlds: the best OS core (3.1.4), and the more handy applications some of which came with 3.9.

I have already performed the 3.9 + 3.1.4 integration several times: It requires some work, but it is not voodoo magic by any means.

Always nice to see additional development, even if it means more fragmentation.  I'll probably pick and chose from 3.1.4 components (once released) to add to my existing 3.9 systems.  Of course I don't expect anyone to support these hacked together kludges beyond myself. 

Hello.

ORIENTATION:
The A501 is usually fiitted inside a screened can so you wouldn't be able to see the components at all.  But if you were to remove the can then you would find that it fits with the component-side facing up.  This means you would only see the bottom side of the board from the trapdoor.
I've never come across a Marpet MP500A but I would imagine it's the same deal.  The A501 has its connector offset from centre to dissuade you from fitting it the wrong way around.  Is there not something similar with the Marpet MP500A?

A300 PSU
I think a PSU from an A600 machine, provided it is in good working order, should be able to power your A500.

BATTERY
The AMIGA is fine with no battery, it just means you will have to set the clock manually each time you power on.  If all you're doing is gaming then of course the clock won't really matter at all.

VINEGAR
Be a bit careful with leaked NiCAD batteries.  Some explanation:
NiCAD batteries use potassium hydroxide as an electrolyte.  When this leaks from the battery it reacts with the carbon dioxide in the air and forms potassium carbonate.  I believe this is the white powder-like material you see hugging around the battery itself.  I would be interested to learn more about this from someone more knowledgable than me.
But, importantly, there are probably also cadmium salts in the mix here and these are quite toxic.  So take some care.

You may also see some green material on the leads of components and ICs.  I'm not certain but I think this is Green nickel hydroxide.

I'm not sure about neutralising with vinegar.  I've heard this as well but I'd like to further understand the science before I apply vinegar to any of my own AMIGAs.  Are there any chemists on these forums?

'I for one have been waiting eagerly for this update ever since it was announced - granted I use 3.1 today so for those of you using non retro versions it may not be such a big thing, but for me it serves as a way to fix bugs while still keeping it as original as possible

Thanks for the links.

I like the one with the bracket, I could convert it to a faceplate.

I know that SD cards can be a but finicky from having a Raspberry Pi.