Embassy legalisation for use in Uruguay
Start with what is absent. Uruguay accepts a simpler single-step certification, so no mission attests anything and the consular route does not apply. Embassy attestation for Uruguay is not a stage to plan around, and once the British side is done the sheet is finished as it stands.
The register's mark and the one that follows it
A registrar signing a fresh copy is saying one thing: this sheet matches the entry held in the register. That is what makes it a certified copy rather than a photocopy, and it is why the copy can travel while the certificate you keep at home stays put. It says nothing about how the paper will be read abroad.
The second mark answers a different question. It vouches for the registrar's signature, so that a reader with no way of knowing British signatures can still trust the page. Anyone trying to legalize documents for Uruguay needs that second mark, and a sheet carrying only the first one is halfway there.
The Manchester → Uruguay route step by step
Manchester Register Office at Heron House, 47 Lloyd Street, Manchester M2 5LE prints the certified copy of a birth, marriage or death entry. From there the sheet goes to the FCDO Legalisation Office at PO Box 6255, Milton Keynes MK10 1XX, which adds the mark Uruguay reads and posts the paper back.
Distance barely enters into it. The second office serves the whole country from a post box, so a Manchester address neither helps nor hinders, and an address in Montevideo changes only the final envelope. Consular legalization for Uruguay would have added an appointment and a diary; without it there is no place anyone has to attend.
What the two marks cost you
The register office charges for the copy it prints, and an official fee applies to each sheet the Legalisation Office marks. Nothing follows from abroad, so document legalization for Uruguay has a ceiling that is easy to work out in advance. Searches for embassy legalization for Uruguay from Manchester usually come from someone budgeting for a stage that is not there.
Timing splits the same way. The second stage takes 7–10 business days, or 2–3 business days if you pay for express, while the copy itself is usually a much shorter errand. Everything left over is postage, so order both marks in one run and let the envelopes, not the offices, set your deadline.