As a NMRA member,past NMRA Division BOD, I would agree it would be great to form a relationship with them, HOWEVER, please note the registration for this year NMRA Convention in Atlanta is $149.00, Spouse- $60.00, Children-7 to 17- $30.00, none of the registrations include admission to The National Train Show- not alleviated with the NMRA.
Suddenly the $5.00 admission to the Strasburg shows is a BARGAIN!!!
My TCW, John
Having been also associated with the NMRA for a while now, and also somewhat involved in a relatively recent attempt to find some way coordinate the NMRA Nat'l with the OSN, I can pretty much tell you that it simply is not going to happen and that comes from both directions.
The simple cost of the NMRA Nat'l is always cited as a major impediment, and that is usually coupled with then little or no interest in what the NMRA Nat'l offers overall.
In sum, it's been a major "why bother" from both sides of the aisle; same story for the other non-HO scale and the Narrow Gauge.