There's a points list at https://spacequest.net/sq1/pointlists/
Note that this is listed as the EGA version. The point list labelled VGA version is for the remake.
Note though that that points list only gives 202 points; while all 100% runs have gone for the true glitchless maximum which is 205. (The extra points are from doing first trunk and then vent on Deltaur.)
Hard to guess where the problem is without more info. IIRC, you need to drop the first grenade, go back (without losing your disguise), give the ID again, and then get the second grenade.
Still hard to know what the problem is without more info (whether you're playing in ScummVM or DOSBox; if ScummVM, regular or UrQuan's; and if DOSBox, what cycles). If all else fails though, try changing to a lower speed (Fast if Fastest is too fast; Normal if Fast is still too fast).
GoG ScummVM. I don't know how to change speed on that. I'm not trying for any speedrun record. It's just that speedrunners are the best at helping to solve issues like this.
Copy what TacoAdventure does in his ScummVM 100% run. Esc brings the in-game menu up regardless of emulator, you can change the in-game speed setting there (and indeed you can see that Taco temporarily switches from Fastest to Fast for that specific sequence).