Here's a photo I found of a brutally removed SMLE charger bridge in my collection:
https://www.milsurps.com/images/impo...tuff0101-1.jpg
Note the barely flared end of the rivet pulled from the action body. Would be about invisible...
Generally, on most SMLEs the heads and tails have been linished off so well you can't see the rivets at all. No.4 charger bridge rivets (if installed, i.e. those Fazackerly welded bridges which never had rivets) usually are easier to detect.
All this weighed on my mind so much I plumb forgot to look at my various 1888s with the added guides. Only photos I have are of the non-modded version. MAYBE, if I remember all the folderol we'll have more pictures this week.