I too like TRF and I appreciate that they use the original numbering system for parts, mostly. This means I have to have a factory parts catalog, but that's an invaluable resource in itself.
The other vendors with their own numbering systems make it difficult to compare and be certain you are getting the exact item, or something similar that someone has decided "will do".
TRF's biggest problem is backorders. Just a couple months ago I received a post card that my exhaust system ordered in 1999 has finally arrived!
TRF's focus seems to be on the IRS cars, which is fine.
All the U.S. vendors would do well to expand their inventory with some of the high quality parts being offered by Cambridge, Revington, Racestorations and others in England.
After 21 years in the advertising business, I can tell you that producing a catalog and distributing it is a very expensive and time-consuming task. The Internet is rapidly changing this aspect of the business and has also made finding and acquiring parts a whole lot easier than it was in the late 1970s when I first started working on LBCs.