Treating and cleaning rubber bumper on MGB

[MGALUVR@aol.com]

I have a 78' MGB with the rubber bumpers. The bumpers are in pretty good 
shape considering their age, but could use a little "cosmetic boost". Does 
anyone have a suggestion as to what to use to treat these rubber bumpers? I 
used some Armor All  and it helped some, but I prefer them to be a little bit 
darker. The Armor All seems to soften and enrich the rubber, but doesn't make 
it darker. Any suggestions? Would  tire blacking do any damage to the 
bumpers? Please help if you can. Thanks in advance..........Bill in Missouri

62 MKII MGA Roadster
78 MGB Roadster