I've been going through the Lego astromech parts and building droids. From the three design rules I just made up, here is what I've come up with:R2-P4
One of my favorites. The dome from the 75032 X-Wing Microfighter and body from R4-P44. New dome print style is too high but I don't mind the old body print style.R2-G0
This droid has the dome from R2-Q2 and the body from R4-G0. With white or flat silver legs. New body print and old dome print. Works quite well. I'm using the dark legged version for an Imperial scene and the light legged for the Rebels.Three Red R2
Three red R2 units using the dome from the 75039 astromech and the bodies from R5-D8, R5-D4, and R4-G0. Nice additions. R2-D8
A colorful droid with a light gray R2-D2 dome and R5-D8 body. Pretty nice.R2-J2
Another pair of astromechs with R2-Q2 dome and R2-D5/R2-Q5/R5-J2 body. Not too bad but I would have like to have seen some copper on the dome.R2-U1
The opposite pair of above. The color scheme works better in my opinion though. Made with R2-Q5 dome and R2-Q2 body.R2-U2
Another pair of droids with the R2-D5/R2-Q5/R5-J2 body and a R4-P17 dome. Not too bad but would have been better with copper in the dome.R2-P1
Simply R4-P17 with dark red legs. I have seen photos from the movie with R4-P17 with dark red legs so maybe he got a paint job.R5-M2
A couple of junk droids using R2-D2's body that don't follow my made up rules but are in the movies. Passable renditions. R5-M2 is made with R5-J2's bucket and R3-T2 is made with R4-P17's dome.R2-U3
A Clone Wars hybrid using a R8-B7 dome and the new dark blue R2-D2 body. I quite like the color scheme but would have preferred a standard style dome, but hey if Lego can do it, so can we. R2-U4
Another Clone Wars hybrid using R8-B7's dome but with the R2-D5/R2-Q5/R5-J2 body. The copper and gold don't quite
A pair of green Clone Wars hybrid droids using R3-D5's dome and R2-R7's body. Good color scheme but wish it was a standard style dome.R2-A7
Simply R2-A7 with white legs. Not bad but a Clone Wars droid.R2-U7
A droid using the original style dome. R4-G9 dome on a R2-D5/R2-Q5/R5-J2 body. Good color scheme. Probably the first custom astromech most of us made. R2-U8
A hybrid using the old style dome and a Clone Wars body. Made using R4-G9 dome and R8-B7 body. Not much to like really.R2-B7
More hybrids using Clone Wars bodies. These are made with R2-Q5 domes and R8-B7 bodies. Not too nice.R5-Q2
Now the R5s. Made with a R4-G0 bucket and a R2-Q2 body. My favorite of the R5 customs.R5-Q5
Another R5 using R4-G0's bucket. This time with R2-D5's/R2-Q5's/R5-J2's body. Pretty good.R5-Q2
A pair of R5s using R5-J2's bucket and R2-Q2's body. The copper on the bucket is the only thing that throws the color scheme off slightly.Three Red R5
Three red R5 units using R5-D8's bucket and the bodies from the 75039 astromech, R5-D4, and R4-G0. Good color schemes.
Well that's it. We're getting more astromechs this year and I've been counting up the additional droids I might put to use. The names I use for the droids I made up with rules I also made up (U is for unknown) but it might be fun to vote on 'official' names for them, at least for FBTB. I didn't make up the names for R5-M2 or R3-T2. I don't think I used any official names on any of them but please correct me if you know better.
Cheers and happy building!