Another PRSI Class D and contributory pension question

I started working in a semi state in October 1986 aged 16 and paid a PRSI Class A contribution weekly until promoted in May 1990. From then until now, I have paid Class D. I'm due to retire from my job aged 60 in November 2029, but can work beyond that, paying Class A in a new job to boost the number of those contributions if necessary.

I've received different opinions of whether or not I may qualify for a contributory state pension, and what the PRSI requirements I must fulfil to do that. With mixed contributions, I'm told I need 260 Class A to qualify for a pro rata contributory pension, but that's something I know nothing about.

Would appreciate any informed opinion of what my entitlements may be, and how best I could proceed to boost my chances of securing something from the state. The occupational pension I have is from a scheme that was mullered during the FEMPI era and the pension once in payment will not change much over time. Thus I'm looking at supplementing that with a state one if i can qualify for it.

Firstly get a copy of your Prsi record from Dept. of Social Protection.
You already have over 3 years of class A contributions.

You are correct that if you reach 260 reckonable paid contributions you would qualify for a pro rata pension.

When you retire at age 60 you have various different ways of gaining extra reckonable Prsi contributions up to maximum age 70.

These can be from class A employment, class S from ARF drawdowns, voluntary contributions based on either class A or class S and class A Jobseekers credits.
You could also get up to 2 years of reckonable change of status credits.

You could gain over 14 years of reckonable contributions up to age 70.
You could also qualify for Benefit Payment 65.

Start by reading this post. It's a bit out of date as it was written before the option to deferr the pension up to age 70 existed, but will give you information on what's possible.