My own personal observations are that when blending "new work" into an original car - Most people use entirely too much paint which sticks out like a sore thumb... you have to do it as crappy as it was originally.
To blend frames/subframes -I have mixed some roofing tar with black paint and rubbed it into the frame with a rag... it doesn't stick out and will not result in over spray anywhere.
In this shot you can see where I rubbed the paint into the subframe...
A light coat of semigloss on the calipers and then file/sand the machined areas like original...
Casting Date
Assembly date
Here is a photo of the entire subframe with the tar paint mixture blended into the frame...
and what the car looks like after a few years...
__________________
~JAG~
NCRS#65120
68 GTO HO 4 spd Alpine Blue /Parchment 2 owner car
#21783 71 Corvette LT1 45k miles Orig paint - Brandshatch Green - National Top Flight - last known 71 LT1 built.
71 Corvette LT1 42k miles Original paint - Black - black leather - only black LT1 known to exist.
NUMEROUS Lemans blue Camaros,
Monza Red and Daytona Yellow Corvettes
& a Chevelle or two...
Survivors, restored cars, & other photos
https://picasaweb.google.com/lh/myphotos