Sadly, it appears we're scoffing at the idea of freelancing equipment here. Sure some people have made assets before that are freelanced, but those in the past were not necessarily different than what we have now. We have to keep in mind that many of the early locomotives and other rolling stock were in fact freelance, or scratch built in the companies own shops. This was particularly true of many narrow gauge and logging railroads who needed specialized equipment. Even some of the bigger railroads, such as the New Haven, for example, had their own freelanced equipment. The Roger Williams trainset, a multiple unit RDC trainset, and the more famous FL9s and other equipment, were all custom. The FL9s went on to live many more successful years and their technology has become the norm for many dual traction environments today.
Transit and trolley companies seemed to always freelance, or customize equipment they purchased on the market. The old Boston Revere Beach & Lynn (BRB&L), aka The Narrow Gauge" was a 3-foot steam narrow gauge railroad that ran from East Boston to Lynn. In the early 1910s, GE assisted them in electrifying their lines. At the time, the had a choice to go with 3rd rail and to upgrade to standard gauge, which was something they should have done as that would have guaranteed their survival. Instead they chose to go with overhead catenary and added trolley motors to their Laconia Car Shops- built passenger cars. These were standard passenger cars and parlor cars with a motorman's controls added to the ends and trolley poles on the top. Sadly, these customized trains were too heavy and never had the speeds that a real electric could be capable of.
In the end, the Narrow Gauge went out of business just before WWII. If they could have survived, I'm sure it would have been a different world. In the early 1950s, however, the ROW was converted to standard gauge and rebuilt as far as Wonderland Park in Revere, MA. This is now the MBTA Blue Line, which features dual-mode electrics that run under full catenary above ground and 3rd rail through the East Boston tunnel and into Government Center in downtown Boston. There are plans, amazingly how things go in reverse, to rebuild the line back to Lynn.
So, don't disregard custom or freelanced equipment. There's a gem there somewhere which may be the future technology elsewhere.