Happy to wait for when you have time! I already owe you.
There's some potentially suitable code in C, which could be easily modified for our purposes I expect, here...http://www.eex96.com/?p=4#more-4
I have little doubt the wireless data transmit/receive pairs can be made to work with *either* TTL or RS232, assuming the relevant logic levels are taken into consideration.
The BR355 outputs RS232 which is the inverse of TTL, as we have previously discussed. Its data are inverted by a transistor before being transmitted over the wireless data link. If using TTL, the data signal could just be applied directly to the data transmitter module's data input pin.
At the receiver end, the data are converted back to RS232 by another transistor connected to the receiver's data pin. That is done because the nixie clocks I have are expecting RS232 (out of a BR355). Inside the clocks, this is converted yet again to TTL by another transistor inverter.
As far as I can tell, the TTL output of a suitable GPS receiver module like the one from Adafruit could be connected directly to the data pin of the 433MHz (or 315MHz or whatever) transmitter and, at the other end, the data pin of the receiver could be connected directly to the relevant pin of the Arduino, since the wireless receiver outputs TTL.