Re: ? on fel for B7100
I can't imagine anyone being adversely affected by the information that you have provided so far. I am a little suprised to learn that there is a LA300 mounted on a B7100, regardless of the LA300's numerical suffix. There probably isn't that much difference between a LA300 and a LA300B, anyways.
kubota makes a LA350 and a LA350A for my B2150; on one the hydraulic controls stay on the tractor when the FEL is removed (I suppose that this is so the controls can be used on other implements such as a front blade), and on the other the hydraulic controls stay with the FEL when it is removed.
As mentioned earlier, the two Kubota FELs sold specifically for the B7100HST are the B1630 and B1630C, where the difference is that one is compatible with a mid-mower and the other is not.
In either case, if the LA300B will fit on your B7100HST, then it would make sense to me that any LA300 will fit on any B7100HST. There may be limitations such as mid-mower compatibility, but I'd say it will fit.
For the benefit of anyone else reading this post, the FELs for the B7100D/E (gear drive models) are totally different from the FELs used on the hydrostatic transmission B7100s.