How on earth was the shire provisioned with its various industrial goods? Cast iron and welded items seem to be common, but the population seems to be entirely comprised of landed gentry and agricultural workers. Presumably some vast network of enslaved goblins were forcibly enlisted, but what actually gives? Don't even get me started on the rampant theft that must have been perpetrated by the people of Rivendell...
I'd like to propose that this question be removed by the mods for soapboxing- accusations of Elvish theft are clearly antikwendist in intent, not to mention the goblin apologism... If you are indeed after a serious analysis of the Shire's economy, then any real academic source would point to its anarcho-capitalistic agricultural system, which by all measures seems to have worked highly efficiently. A system where everybody minds their own business, is given the freedom to realise how much everybody really needs, and where land and good company is more valuable than any kind of civic, progressive nannying. An example we would do well to follow, I hasten to add.
I think you're underestimating the trade relations with the dwarves of Erebor (both pre- and post-Smaug) and the dwarves of the Iron Hills during the Occupation of the Lonely Mountain.
Recent chemical analysis of the famed "Pipe-weed" of the Shire has concluded that the Pipe-weed contains a highly addictive chemical. The Shire exploited that highly addictive nature of pipe-weed as a trade product selling it throughout Rohan and Gondor for high prices. It is believed that at one point 42% of Rohan's GDP was spent on the purchase of pipe-weed prior the War of the Ring. This is one of the primary cause for Rohan's relative decline. The discovery of pipe-weed in Isengard lends credence this theory. Saruman likely introduced pipe-weed to Rohan to weaken Rohan for invasion.
The profit that the Shire made from the sale of pipe-weed was source for the Shire's wealth and industrial goods.
Unfortunately, you seem to be losing track of the Dwarven settlements in Ered Luin; while the Blue Mountains were generally the least wealthy of the Dwarven settlements, they still produced a great deal of goods. A key resource missing from their territory was arable land, though. Following the collapse of Arnor, the dwarves were restricted to trade with the fading elven lands of Lindon or with the Shire.
Halfast Brandybuck's personal journals of his business ventures, while generally frowned upon in the Shire, contains several mentions of initiating and continuing trade with both Firebeards and Broadbeams from the Blue Mountains, and these trade routes appear to have been maintained after Brandybuck's death. Dwarven traders brought manufactured goods in exchange for Shire-grown foodstuffs. These supplemented the limited manufacturing industry of the East Farthing.