Rod,
The marriage in Maughold has only Alexander Murray & Jane Vaust married 5 Aug 1824, with no parish other than Maughold given for the groom. The following entry reads Charles Jas Tinsdale & Isabella Kaighin married 15 Sep 1824. Chas from Bolton-le-Moors, Isabella a widow from Ramsey. It is unusual for the Maughold register not to give these additional details when they existed.

Constance Radcliffe's book about Ramsey has some information about the Voast/Voste/Vaust family, including the MI for Captn Charles Vaust (1770-1853), and a mention of his wife Jane Inch, which you have probably seen, but nothing about their children or daughter Jane. IGI has Jane Voast bapt Ramsey 21 Dec.1799, and their other children under "Voast".

Charles's burial in the Maughold register is interesting:
Charles CHRISTIAN aged 79 (alias VAUST), Ramsey, buried 4 Oct 1853.

His will is on Brian Lawson's index, and might throw some light on what happened to his daughter, and where his grandchildren were in 1853:
VOAST, Charles 1853 Mau Epis no. 88, LDS film no. 0106454

It would also be interesting to see what the story was with that alias, if mentioned in the will because of being a legal document.

CR mentions a George Murray as Captain of the town of Ramsey in 1761, but nothing about an Alexander Murray.

It's a long shot, but could he have been Alexander Murray HAY aged 64, of Glen Auldyn, Lezayre, buried Maughold Jul 19 1864?
Will: HAY, Alexander Murray, 1864, Lezayre, Epis. no.103 LDS film 0106466.

Alexander Murray Hay & Elinor Mylchreest married Maughold 24 Apr 1842. Alexander a widower. They had a son William Shaw Hay bapt Maughold Parish Church 20 Aug 1845. Private baptism. William Shaw HAY infant, buried Maughold Jun 7 1846.

I can't find an earlier marriage for Alexander Murray Hay, widower, only the one for Alexander Murray.

Eleanor HAY aged 65 yrs, Glen Auldin, Lezayre, was buried Maughold May 9 1878.

Sue