[The V1p3r]

Hello everyone. I am in the market for a typhoon and I noticed that palmers rebuild service for typhoons is $100 more for pre P1000 serial typhoons than standard cost. Is there a significant change in the design or parts spec in the different eras of typhoons? Does P1000 even imply 1000 guns made, or did they start the number with (10) and 00 is the first model?

Is there a list of possible changes in build to typhoons somewhere? I am unable to locate it on their website and while it won't dissuade me from a good purchase, I am still curious.

Thanks.