help with a BF?

I resently found a nice little BF for sale and was wondering if i could get some help on identifying it.

I see they are the same as a Avery R and also there are BFW's, BFD's, BFH's and BFS's how do i tell the difference between all of these?

The one im looking at has a wide front, is yellow, (not sure if all the avery ones were red) and has char- something power steering. Also is the powersteering factory?

Thanks
Taylor