I'm fully in agreement that many spoons of the period appear to be two part constructions, even when it is not the case. There are a number of reasons for this and I'll try to set them out in a logical way.
In two-part spoon construction, the drop was not just a decorative element, it had two very practical reasons to exist. Firstly, it was a structural necessity providing ample area for a strong solder joint. A butt joint of bowl to stem is very weak and without the area of overlap it would likely snap if the porridge was a little too thick. Secondly, the drop was a wear buffer, the thickness it provided to a spoon bowl's resting area would not allow it to wear through quickly.
It is apparent that, back then, change was not the saleable commodity it is in the present day. If you look at the evolution of spoon design from 1700 to 1850, it is remarkable how little they really changed and how minute the increments of change were. To go from Hanoverian to Old English over a span of decades is slower than a snail's pace.
With the advent of available dies to make one piece construction practical and drops structurally unnecessary, it's clear that the buying public still expected drops on the backs of their spoons, which is why we see engraved pseudo-drops on some dropless spoons of the period.
Smart businessmen that smiths were, drops stayed and and spoon dies were adapted to form drops along with the bowls, they still prevented wear-through, they pleased the customers and it certainly did not hurt if spoons appeared to be made in the same, time consuming, way as they were in the past.
However, the making of a spoon, by hand, with a die or swage is not as clean or as neat as we may imagine. The metal is roughly trimmed to shape, then stretched and thinned were needs be, elongated and thickened were needs be, and then the oval flat end mashed into bowl & drop. Here the process is not over, it comes out rough, spoonlike but still very crude and it takes much afterwork and artisanship to turn it into a finished spoon.
Although the photo example of the stages of spoonmaking (four posts up) shows a 19th century example, it still applies to a 1750 Hanover, after diestamping it is still only half done. The bowl edges have to be trimmed down evenly and the drop's shape refined - all by hand filing, then scrapers, then scotchstone - followed by an arduous polishing out of the tool marks and any marks from flaws in the die. In the photo of the spoon drop (one post up) the marks under the arrow are file or scraper marks that were not polished out well, the bowl appears asymmetric because of uneven trimming of the edge. The apprentice or journeyman responsible may have had too many beers with his breakfast, or then again, as many were pieceworkers, I'm sure they cut corners wherever they could get away with them.
Aside from, but in support the above theory, a solder joint in a two part construction will always show as a thin line of varying color, sometimes with a bubble pit or two. Very difficult to see around the edge of a drop, but more easily discernable on the front of the spoon where the stem joins the bowl.
All that said, I have to admit that I have nothing to back it up but a freewheeling imagination... so have at me... and could someone please dig up some respectable source material on the subject.