Plans to create a "key cultural hub" at Llandudno Museum are set to be helped by £140,000 of council cash.
In total, £1.367m of the £1.5m cost of the work has been secured from sources including the Heritage Lottery Fund.
Decisions will be made on other grants and funding totalling £450,000 in the first half of 2018.
At a meeting on Tuesday, Conwy council's cabinet will be recommended to approve making £139,344 available in case none of these are successful.
Llandudno Museum is owned by a charity and puts on exhibitions, workshops, lectures and family activities.
A report to the cabinet said in order to turn it into a "key cultural hub", it needed more interactive galleries and exhibition areas as well as improvements to the cafe, entrance and shop.
£1.5m plan to "revitalise" a Conwy county museum is a step closer after the project received a £120,000 grant.
The Heritage Lottery Fund (HLF) awarded the funding to Llandudno Museum, with a view to granting a further £862,000.
Plans for the project include creating a family space for learning and community use, and installing a lift.
Roy Haley, of Llandudno Museum, said the funding would help to produce "a revitalised, engaging and modern experience".
"We still have to raise more funds to complete the project, but the practical advice and financial support of HLF is a massive help to the museum," he said.
The grant has been awarded during the Welsh Museums Festivals Week, that runs for a week until 1 November.
Ref BBC