JT vs, BR models?

[gnappi]

I have a GR8 4.5" BFR in .44 magnum and I have several questions about BFR revolvers, while there's a lot of BFR owners there is very little info available (see PS below) about them.

1a. Is there a difference between JT and BR serialized models?
1b. If so are they 100% compatible?

2. Does MR have rubber replacement grips for the BFR readily available?

3. Why isn't the .454 or .44 magnum available in a 5 shot version but the .45 ACP is? THAT is weird.

4. Why isn't a .480 cylinder (NOT .475/480) available?

5. Will the .500 JRH model handle (without any issues) the .500 S&W special cartridge? JRH brass is EXPENSIVE and Starline does not offer it.

6. It seems as if the wide spur hammer was replaced with a narrow type? Why? and is a wide spur hammer available?

7. FINALLY, it seems as if the only available 5"-5.5" barrel models available without going custom is the 500JRH. Why?

Oh PS... the "REQUIREMENTS" for getting a login here by answering arcane questions about MR's other products IS preventing a LOT of shooters from participating here. SA revolver owners do not know diddly or care about MR / Kahr's other products and are not going to waste time researching products only Kahr fan boys would know to get a log in here.