@ Bittyboy.
I have to admit I didn't know that editing your listings with extra photos resulted in them disappearing. I've rarely paid for extra photos, there's only so many angles you can take pictures of an old vase from without becoming boring !
It does seem wrong as you paid for them and then edited a different part of the listing. Perhaps ask support if you inadvertently did something wrong and if there is way to avoid it happening again ?
It might well take you a while to get things right here, I've had years to play around with titles to see what, if anything, gets extra visibility. I started looking at GS back during Covid lock-down due to boredom and something someone said here on the boards about not having exactly the same ad. title here and on obay, which is what I was doing. GS will show the ad. from the larger site and then ignores the other (from ebid) as a duplicate. My sales did increase, so I experimented further.
Perhaps try starting with a small sample of your ads. I mentioned earlier that some of the later types have names (Yale / Chub), why not edit them to show the name first? That's all I did after trying Robbie's advice about "Art Deco" being too generic. It made my title more specific to the manufacturer's name and straight away if I searched for e.g "Bagley Art Deco Glass" Ebid and some of my listings became visible.
It might work for you and as you know far more about locks than I do, you know what potential buyers might look for and which words need to be moved to the front of the title. If having the name first in your title gets views, that's an improvement, if it doesn't try something different.
Back in glass, another feature that I hope will attract buyers is "Uranium". If after a few months still nothing has sold, I'll edit all my listings with Uranium in the title to move it to the first(strongest) word. It's all hit and miss as Google goes to great lengths to make its workings opaque and "gaming" proof.