I just tuned up the Cambridge this weekend. there are a couple of things that are different due to temperature concerns. Off the top of my head since I am about 5 hours from home till Friday they are as follows.
Oil viscosity, both in the crankcase and oil bath air cleaner, is thinner.
Accelerator pump shot is different, more so as to compensate for the condensing issue someone mentioned.
On my 51 the fast idle speed is not adjustable and I don't believe it is on either of yours. But if it is, check that. Wouldn't hurt to just tune it up altogether.