Question about old british passport

Hello every one
My grandfather has old British passport (colony and protectorate of Kenya) subject of Quaiti.
Quaiti was colony of great Britain.
Nationality: British protected person
Expire date: dec 1968
We asked Uk HM to renew it , they saied use this service (gave us a link).
We did everthing in that link.
They gave us a declaration form we signed it and sent to their office in Liverpool.
We sent the British passport , The passport of Yemen ,declaration form and 2 photos.
They saied the service take at least 6 weeks.
Three month later nothing happened the status (declaration form received, being processed).
We contacted them to tracked the application they sent us a message ( your application going through examination process).
The Yemeni passport expired on 2010.
What can we do now ? Why they take so long to reply us ?
We afraid they will refuse our application.
Any advice?
Thank you.

I think this applies;

In most cases you would have lost your British protected persons status if you gained any other nationality or citizenship.

So that's probably why no British Passport is forthcoming. It's fairly useless anyway;

Rights as a British protected person
You:

can hold a British passport
can get consular assistance and protection from UK diplomatic posts
However, you:

are subject to immigration controls and don’t have the automatic right to live or work in the UK
aren’t considered a UK national by the European Union (EU)

I knew that.
It's almost useless but if we have the passport that's enough because we will be so proud of anything conecct us with this great country.
If he lost his status as british protected person why they didn'n refuse his application until now?
If they see other passport (yemeni one) I think this is a reason to refuse it.
Why they take so long? Three months to see he lost his status.

Thank you Wanderer for your rypling

Nothing else.
Can any one give me a good reason why they take alot of time?
3 months and half