I use a Flymo Compact 300 (circa1997). Blade 30cm, part no.W5126439, with blade tips angled up approx.15*.Have purchased new blade 30cm, part no. W5127629 (for Flymo Micro Compact 300 Plus mower) with blade perfectly straight. Advised the blade is interchangeable with original blade. Am I to believe this? Serious answers only please!