Advice needed for B-26 Marauder in 1/72

Well my friend i dont know if 30g is to much, right now i am doing a B-26B in 1/48 and to figure how much weight should i add tho the nose of the plane what i do is that i assamble it and instead of glue i use masking tape just to place all the pieces together (fuselage wings tail etc)then i use two little suports so that the wings would rest in this suports( the plane wont be in touch of the ground, would be resting on the suports) those suports must be placed where the main landing gear would be, then i add clay just over the nose, keep adding until the plane is "balanced" see what the weight of the clay is and then add it into the plane, wether nose or engine nacelles, i hope i made myself clear on this one, is kind of hard to explain this things and even more when English is not your primary language. Hope it helps!
Oh, if you need anything else just let me know and i will be glad to help!

Saludos!
Regards
Hector Reymundo

hey Mitchell:
what I use is B-B's and super glue, they are easier to install then fishing weights and you don't need to open up the fuselage to wide to get them in either, and you could buy a 5 lbs box of them at Wally World for about $5.00 in the sporting good dept by the air rifles, also they conform better to the curvature of the fuselage too, maybe on you next project try them instead of fish weights
have fun & relax
Cuda