Hmm. I'm not sure about some of this upcycling. It's better than chucking stuff out but I see things on eBay that I would have liked to buy and own until someone helpfully turned (e.g.) a specialised precision instrument into (e.g.) a lamp and basically made it 99.7% useless. You've got the sellers of pimped theatre lights - "Own a piece of film studio history" meaning a gold plated Strand patt. 45 that most likely lived its working life over a primary school hall. "Lovingly refurbished and upgraded to modern standards," meaning it now looks comical, can't be used for its intended purpose because it's got a bayonet holder and is now only good for adorning a set of modified bar stool legs illuminating someone's parquet floor.
I bought some horn PA speakers for which the seller was giving out all sorts of suggestions of how they could be used as lamps, planters etc. He was incredulous that I wanted to use them as PA speakers. Then there was an electronic organ. 'Is it just the valves you want out of it?' he asked, 'or are you converting the console into a digital instrument?' 'Er, no, I want to plug it into the wall, sit on the bench and play music on it.' He didn't look convinced.
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If you're double-insulated all the way through there's no need for an earth - I think you can buy assembled lampholder-cordsets that inherently give you compliance with this. OTOH, if you replace the battery cover with one that supports the lampholder and lets the flex back out upwards behind it, you've no need to gut the AVO and could return it to normal just by putting the original cover back. One mod I would sanction would be to connect the appropriate AC current range in series with the lampholder, so that it indicates the lamp current. Or line voltage. Actually, I might do that...