Just acquired a new Glock 21SF and would like to add an OEM Glock extended slide stop lever. I am having a tough time finding the OEM part number for a unit that fits G21SF models. According to the Glock Parts Order Form found here,the Stock part info reads as follows: "SP 05306: Slide Stop Lever & Spring - fits only G20-G20SF-G21-G21SF(standard mag catch)-G21Gen4 -G29-G29SF-G30-G30SF only (marked 5299-1 on back)" The Extended Slide Stop Lever and Springs have part numbers 7496, SP 07489 and SP 01034 yet none of them have G21SF listed under model type let alone any other SF model. SP 01034 however, has G21 listed. I noticed stock part SP 05306 is found on the G21/G21SF. Does this mean the extended part SP 01034 also works on the G21SF? Glockmeister sells the OEM extended slide stop lever for SF models yet they have a proprietary part number listed for the item. They typically use OEM part numbers for their items but for some reason they don't for the SF extended slide stop levers. BTW, I understand Vickers also sells an extended slide stop lever. I'm wondering if this would fit the G21SF. I'm curious to see what G21SF/G30SF owners have installed on their firearms with respect to extended slide stop levers.