Only a selection of the marriage records for St Thomas Dudley appear to be on line and they don't go back this to 1794. They are unlikely to give you more than the information you already have as certificates weren't introduced until 1837 and the IGI says that it is an extracted marriage record for locality listed in the record. The originial parish registers are at Dudley Archives (Mount Pleaseant Street, Coseley, West Midlands), with microform versions at Worcestershire Library and History Centre (
WLHC@worcestershire.gov.uk)
Whilst I was looking, I found some burials (later dates, so I don't know if they are 'yours'
Mary GRIFFITHS February 22nd,1817/Elizabeth GRIFFITHS March 1st,1827/Thomas GRIFFITHS April 15th,1835/Thomas GRIFFITHS (Son) March 24th,1864/Rebecca GRIFFITHS March 5th,1875.
Agnes GRIFFITHS died September 6th,1882/Edward GRIFFITHS died December 10th,1889.
Eliza Mary GRIFFITHS Age 6 died October 26th,1883 (Union St.)/George Victor GRIFFITHS Age 10 months died February 11th,1888.
Tablet - stone.
Sacred to the memory of Thomas GRIFFITHS/of Wellington Road,Dudley.Gentleman/who died on the
24th March,1864 in the 54th year of his age/This tablet is erected by his fellow Townsmen as
a record of his valuable public services during many years to the town and parish of Dudley.