I've gone ahead and continued with those tins of tuna in place of the motors as they are a close enough fit. Width-wise I've used a simple ruler as a masking template as again, it's good enough for government work.
If you think I'm kidding, a report into a nuclear submarine incident in the UK last week revealed that rather than using a new bolt in a component, the engineer used super glue to reattach a head that had sheared off.
If Putin's reading this, incidentally, I'd be heading for those shelters around about now.
Needless to say ~ okay, we need to say it ~ once you've cut one dog-bone out you can use that as a template for the remaining three.
Alternatively you may wish to use carbon-fibre sheet and a CNC or laser cutter... tho' that's not us, is it?