This was a surprise when I spotted it yesterday, not seen a vase from Merlin Glass before with an impressed mark on the base, likewise a vase with swirling colours like this from Merlin but they are mentioned by Andy McConnell in his book 20th Century Glass. My guess is that an impressed mark was used for a relatively short period after 1983 when Liskeard Glass was purchased by Liam Carey and renamed Merlin Glass. The vase is 15cm high, nice to see such a crisp mark, no doubting it's origin!
John