2nd residency requirements at 5 year point

There are no renewal requirements. After 5 years with your initial green A4 or credit cards sized certificate, you automatically become a permanent resident. Now would be a good time to exchange your green document for a TIE, which while is not obligatory yet, will make life a lot easier for you. You can apply for this yourself in the Extranjeros department in Murcia. It costs 12€ and you can download the forms from the internet. Or you can pay one of the many people who offer the service of taking you and guiding you through the process, to help you with doing it.

Surely after the 5 year point of residency you need to prove your income?your medical cover to carry on living here? 

Why would you need to do that when you're already a resident? The only difference between a permanent resident and a temporary resident, is the number of years since you got your residencia. You automatically become a permanent resident after 5 years, as long as you have fulfilled the residency rules, such as leaving Spain for longer periods than are allowed for temporary residents etc. You've already jumped through all the hoops, now you just need update your document to a TIE and open a bottle of fizz to celebrate!

I thought and still think that at the 5 year point you hafto show medical cover?income to gain a more permanent residentsy here ?or am I talking out my A.?

I'm afraid that I don't know about the health-care bit. I would think that whatever you did to get your original residency, would be sufficient to carry over to your obtain your permanent residency document. If you've been keeping up your health-care payments, then I'm sure that showing receipts for this will be sufficient. There is the Convenio Especial available to anyone who has been legally resident in Spain for more than a year, which involves a monthly payment but more information on that, you'd have to ask someone who's done it or maybe go to the Citizens Advice Bureau Spain's website or Facebook group to ask for the latest update on that. Here's something from the UK government about it.

https://www.gov.uk/guidance/healthcare-in-spain-including-the-balearic-and-canary-islands

As Mags has said just apply for your TIE a very easy process, they are not interested in your medical situation.

I have no idea where you obtained the information that you had to renew your residence after 5 years, I have had mine for over 20 years in Murcia and only changed it from the original photo id which expired on 17/09/208, then for the green A4 paper, and recently for the new TIE never was my health care taken into question.

We have only received our TIEs under the NLV process 6 months ago, so we have several years to go to permanent residency, however, my understanding on healthcare is that you will need to cover one of the following options:

1. If you are of state pension age in the UK, then you can get an S1 so you have free state healthcare in Spain.
2. If you have worked in Spain and made a certain value of contributions, then you will qualify for the Convenio Especial.
3. If you don't qualify as above, then you need to either pay approx. €60 per month per person for the Convenio Especial or pay for private healthcare.