Hi Michael,
You have quoted correctly the GRO index reference, by giving the year, quarter, Registration District, Volume (10b) and page number (410). The marriage that you seek probably took place at Wallsend Our Lady & St Columba Roman Catholic church, since this is on page 409. From what John says helpfully in his reply post, it seems likely that W43 means the same thing for page 409 as 410. The broader point here is that it must have taken place at a non-Conformist church or in a Register Office and in either case it would be recorded in the Registrar's Books, since the marriage took place before the 1898 Act came into force on 1st April 1899. That means you usually can't get access to the details except by buying a certificate. That said, a few non-Conformist churches, especially RC ones, did keep their own books as well, although not necessarily giving all the details that you would find in a certificate. Here, you might be lucky, because, according to the GENUKI website, this church has a marriage register from 1886 onwards available at the Tyne & Wear Archives. Continuing the broader point, you need to be aware of the practice of GRO clerks in arranging Anglican marriages before non-Conformist (NC) & Register Office (RO) ones. Here, Tynemouth Reg. District occupies page 271 to 435 of the GRO book and page 410 is only 9.5 percent from the end of the range, which, in the late 1800s, as here, indicates NC or RO. You can find more about how to "mine" marriages from church registers from the papers on the subject on my website at
www.users.waitrose.com/~whitehousefhc. The papers relate to other areas, but the same principles apply to all areas. It would be helpful to me and others if you would go to the T & W archives (if you live in the area) and report back here on the range of marriages at this church in that quarter of 1891 (Jan to March), giving the dates and parties of the first and last in the quarter, because the number of marriages indicated by John's reply as belonging to the W43 code would be most unusual for one RC church, esp. as the 1st quarter is usually quiet - maybe Easter was early that year. Good luck ! Keith