From what you said it appears that there are no mortgages or other claims on the property preventing its transfer to your name - so the 10% 'trapped buyer' law discount will not apply.
See my Apply for your Title Deeds now
. It says:
"In cases where an application is successful, the purchaser will be requested to pay the Property Transfer Fees within 60 days of a notice to transfer the property. If the purchaser pays within the 60 days they will be entitled to a 10% reduction in the transfer fees or pay the transfer fees in 12 monthly instalments."
So you will go through the 'standard' transfer process as described on pages 45 & 46 of the Department of Lands and Surveys Citizen’s Charter
As you didn't pay VAT on the purchase price of the property you are entitled to receive a 50% discount on the Property Transfer Fees if the transfer takes place by 31st December 2016. For further information please see Reduced Property Transfer Fees
The Land Registry is required (by law) to assess the market value of the property you purchased at its date of sale - this may or may not be the same as the amount you paid. If it is larger you can argue your case and if necessary have the property valued independently.
This is done in an effort to prevent tax fraud as some people under-declare the purchase price in their contract of sale and pay the balance of the purchase price to the vendor in a brown envelope.
This assessed value can cause problems for some people - see Is a property only worth what someone will pay for it?
When you were at the Land Registry, did you ask for the 1980 value of the property? (I may be able to assess the IPT you may have to pay Leptos from when you took delivery of the property up to 2013.)