It will not be short when using the 45-70 or the 40-65.   Both should be 2.10″.  Although my 40-65 Bertram brass is short by about .013″ and it shoots fine in my 40-65.  Remember these headspace off the rim so OAL is not critical when short.  You can shoot 45-70 in a 45-90 and they are at least .250″ short.

Using 45-70 will cause an extra forming step that the 40-65 does not require.  You will actually use a 40-65 die as the first step. It is a lot easier to find 45-70 brass though. 40-65 dies are not that hard to find. So, buy 33 and 40-65 dies if you use 45-70.  If you use 40-65 brass all you need, besides the brass, is the 33 die.   45-90 would require the 40-65 dies too. Then you would have to waste about 1/4″ off the end.

https://www.northernshooterssupplies.com.au/category-s/436.htm  $57.60 USD for 20 pieces plus shipping.  I have bought from this guy before and there were no problems.  Use a credit card and the bank will handle the exchange rate. 

The case mouth becomes too thick during reshaping. That’s why you still need a reamer to make really good cases.

Stefan