I've bought a couple of commonwealth bogie packs (2 in each) to update some of my Mark 1 coaches. These are the current or blue riband type. However, the bogies don't seem compatible. The central pivot hole isn't extended to accommodate the 'fin' on the pivot, nor is the outer end of the bogie sufficiently tapered to allow the body-mounted NEM pocket to swing properly, even with the clip-on rapido coupling mount removed. It would appear that these bogies are designed for the original, not current Farish coaches.
Where did you get them from? Have you got a photo?
These:
https://www.petersspares.com/p/graham-farish-379-442-br-commonwealth-coach-bogies-x2-n-gauge (https://www.petersspares.com/p/graham-farish-379-442-br-commonwealth-coach-bogies-x2-n-gauge)
https://railsofsheffield.com/products/br-commonwealth-coach-bogies-x2 (https://railsofsheffield.com/products/br-commonwealth-coach-bogies-x2)
seem to have the extended pivot hole, and don't have rapido coupling mounts.
Maybe you've been sent the wrong thing?
Neil
I've corresponded with Bachmann—they have acknowledged the problem. If you order 379-442 you'll get the bogies for the Mark 1 Pullmans. Bachmann will be contacting retailers and have advised me to return the items for a refund.