[Hugo barbedo]

for rubber feet for tv's i usually go to the hardware store and buy "door bump stops" i dont know if they are called like that in English,sorry.
they are available in different sizes and in black or brown, they usually match preety good the factory rubber feet

if you want something slimmer for a tabletop there are those felt pads to put on the feet of chairs and furniture

here in my area we have something callled "rubber house" or rubber shop...they have a huge warehouse fully loaded with all types or rubber parts, rubber profiles, feet, covers, whatever is made of rubber they have it

on my BW sets (50's 60's) some of them dont have a rubber dome around the anode connection...if i ever feel the need to i would just use a rubber dome from a modern colour set...dessolder the spring thing that clips to the crt, slip the rubber dome on the wire, ressolder and slip the dome over again. make sure not to leave pointy edges on the solder, make a nice round blob. on moist areas were arcing can occur around the anode connection some people here used vaseline to "seal" around the rubber dome but i never tried it so i cannot say if i recommend

i think the rubber band between the strap and the glass is there to prevent the glass to crack when tightening the strap and when handling the set...i think its important, but i would be very carefull to mess around that area especially on a tv that is already working well...if i wanted to do that i would definetely do it before any other work on the tv...