There are several hits in Google Books (it is possible to order and filter them by date, which helps). The full texts of the earliest hits are not available, so it is hard to see the full context, but some snippets show up in the search.
We have, for example:
When you say that a planned capitalism as a cure for the world crisis is so essentially contradictory that it will prove impossible as a lasting solution, I should wholly agree with you if you are referring to the smash-and-grab capitalism of the nineteenth century.
from The British Empire: its structure and its problems (Johannes Stoye, 1936); this is a translation by William T. Payne from the German original Das britische Weltreich: sein Gefüge und seine Probleme (1935). The original has just "den wilden Kapitalismus" ("wild capitalism") so it is the translator who introduced the more colourful phrase here.
A 1935 magazine article in The Adelphi has
Three hundred years of smash and grab capitalism have not made them capitalists or even bourgeois-minded or steeped in bourgeois morality, because they have never had any bourgeois teaching, only slave teaching.
Earlier uses of "smash and grab" seem to be talking about the actual crime act. There are some metaphorical uses, but not specifically about capitalism. The 1933 book Charles Lamb and his contemporaries by Edmund Blunden (cited under "smash and grab" in the Oxford English Dictionary) includes the phrase
... a literature of the smash-and-grab type or the semi-scientific seems to have some chance of superseding the thorough, persuasive, modulated and interwoven style ...
and from a 1931 debate in the UK Parliament, I found
... there are certain hon. Gentlemen who have been elected as supporters of the National Government and who stand less for a policy of give and take than for a policy of smash and grab.
In summary, the full phrase "smash and grab capitalism" does not seem to predate Reagan himself (born 1911), though it does not look like it was Reagan who originated it. Rather, these uses from the 1930s are from the other side of the pond, and are used with reference to the smash and grab burglaries that were becoming notorious at that time.
