Cake decorating advice please

[bamboo]

I'm making my dad a birthday cake for his 70th later this month and I've got it into my head that I could do a "7" in a fruit cake and a "0" in sponge, something to suit everyone then!

I don't want to pay out for numeral tins so am hoping to carve the cakes but I'm a bit worried a fruit cake won't carve well enough. What do you think? And does anyone have a recipe less likely to crumble? TIA

You can hire cake tins as well you know. I've done it in the past and it was really reasonable.

Thanks Littlefish, that could be the way to go. A quick google doesn't show up anywhere quite as local as I'd like but might be worth a trip, I guess .