Have you established what frequency these receivers are designed for? I'm used to 72MHz, but there are others. I ask, because I wonder if your 72MHz #30 and #46 transmitters will work with these receivers.
If you don't know that, either, you could buy a single conversion HiTec crystal and try it, and if it works, do a range check.
And, if it doesn't work, you're out the price of a crystal and a couple cheap receivers.
Good luck,
Dave Olson