When ever we broke the CR-27 off, we simply let it hang. If its just the screw broken off, (brass) then you might be able to get the screw to back out. Its a simple device. Just a couple diodes. You could make one. Buy one? Don't think so. Do test it. Procedure is in the TM, and its simple. Same with the day tank float. Is the float a one or two bobber float? And as long as you are in there, check the L2, (solenoid). The check is easy, and when you put it back together, turn on the Electrical fuel pumps and loosen the output line on the L2. If you do not get lots of fuel out, the L2 needs to be cleaned also.
Something to keep in mind. When looking for parts, also check the 30 KW, MEP-005A TM's. 95% of the parts are the same, and often have different NSN's and part numbers. ALSO, the 60 Kw and even the 100 KW, have the same common parts. So when you search the E-pay site, keep that in mind. Make it run first. Then make it nice.
The 15 and 30 KW schematics are world famous, for being wrong. It never hurts to look at both, when fooling with the electrical system. In theory, you can use the 30 KW schematics to work on the 15 KW. Wire numbers are the same. Often, if the schematic you are using is not very readable, you can simply use the other sets schematics.