If they are made properly I don't think you would ever lose one. I have seen some dovetails that were not made correctly & were more of a offset track rather than a dovetail & THEN you could lose one. One the old rifles I have seen with the lids missing, it was obvious the dovetails were small & thin & not well made. Also have seen some of the dovetails on the lids sides not parallel & going at an angle like a point toward the front of the lid, so if the lid comes back 1" or so the whole lid will lift out & I personally don't care for that idea, but that is just me.
IMHO, the lid should have a good angle on the dovetail & the dovetail should be at least 3/16" deep (1/4" deep is nice) & it should slide easily & track all the way to the buttplate & have a firm latching feature, regardless of the type.
If it is a little loose, you can usually glue a sliver of leather or felt in a hidden place of the dovetail to take out the rattle when closed.
:hmm: And on that thought itself, how many times do you take a rifle in the woods, shake the H out of the buttstock to hear the patchbox rattle ? Not gonna happen so even if it is a lil loose it would not concern me allot. I would rather have it loose & easy to open, than have the lid stuck & cannot get it off.
:thumbsup: