Cartridge options going forward

Faced with a similar dilemma I decided to try something radically different while I arranged for a rebuild of my Proteus and ordered an SPU Royal N. My tone arm allows some flexibility of effective mass by changing the material of a sub plate on which the cartridge is mounted. I could go from 13g with aluminium to 18g with brass, with the weight of the cartridge, its adapter and screws this gives 35.5g against the cartridges compliance and it seems to be enough for decent bass performance. Ortofon’s own arms have an effective mass of  between 3 and 5g without a headshell and a G series SPU weighs 30g so they would play in the same region. If you know the weight of your headshell  you can work out if your Jelco will give an SPU a decent ride. 
What I did find is that once aligned an SPU with a replicant stylus is a very enjoyable cartridge, to the point I’m not sure I’ll keep the Proteus, but I will send it to Ana Mighty Sound and try the result before deciding.
An SPU Royal GM is the equivalent pickup head to the Royal N, it will be at the limit of your arm’s antiskate adjustment according to the numbers but I found the the Royal N didn’t need nearly as much as the 3g VTF would suggest.
Thats only one option of course, there’s a lot of cartridges out there, If my phonostage could take the output level I’d have been tempted to try an EMT but even a standard Lyra is above optimum.
Meanwhile investigate a Lyra rebuild, I don’t know the US situation but in the UK they don’t charge as much as some other makes and they will upgrade to λ spec, you might even be able to opt for SL but that is a guess.

The Etna is that much better than the Kleos? I own the Kleos and it's outstanding. If the Etna is that much better I would send it to Lyra for a rebuild.

Mtwilke, Get yourself an Ortofon Windfeld Ti then send the Etna back to Lyra to rebuild when finances allow. Then you will always have a back up if something goes wrong and you won't be in this position again. The Windfeld Ti is a great cartridge that punches way above it's price point. It is very neutral and an excellent tracker. You will see this in all the reviews. In the meanwhile you can have an Etna Lamda at a significant savings.

I sent my Skala to Soundsmith for a rebuild, and it came back a much different sounding cartridge, and one I'm none too happy with in general; I wouldn't go down that path again.  I also agree that the price for a Lyra rebuild simply isn't worth it (their trade-in allowance used to be considerably more generous), nor is it necessarily worth the price new.  I have cognitive dissonance thinking that an elderly Japanese gentleman is the last living repository of such skill and knowledge.  What - when he dies, Lyra effectively goes out of business?  Happened to Transfiguration.

I bought an Audio Technica ART9, and don't think I'll ever go back to a $2K+ cartridge, since as a consumable item it's simply not worth it.  The AT gives me 98% of what the Skala gave me when it was new (and in fact does some things better).  AT has been in business making cartridges for 58 years, and it shows in the materials, build and sonic qualities.  Just my 2¢.

To your point palasr - another consideration that has really worked in my system is my second Ortofon - a cadenza black.  My first was a Jubliee which provided years of good playback.

The Cadenza Black mounted on my Vector 4 is as good or better SQ than the more than twice expensive Transfiguration Proteus which bit the dust after 500 hours and also went out of biz at the same time.

Not sure I will ever buy a 5+K cartridge again after spending the last year with CB - also not likely to go OOB.