Iconic AV did offer the straps to some members on here free some time ago, as they had just perfected them & wanted to 'test them out'
I was lucky enough to get a set. They are excellent and fit perfectly.
I guess if you are very handy and have the correct materials and tools, you could have a go at making your own set. Although personally I'd just spend the £15 and have the piece of mind that they are right!
Michael
BV5, BV Avant, MX4000, MX1500
BS 7000, BS 5500
Penta III, Penta II, BL 4000, RL 60.2, RL 35, CX-100 Alu
BL 7000, MCP6500, MCP5500, BL 5000, Beo4 (x2), BL 1000 (x2)