Tony Weston netted a hat-trick in the first-leg tie, with Cole McKinnon getting the other goal for the Light Blues, but Gilmour praised the squad for their variation.
Speaking to RangersTV at full-time, he said: "It is a pleasing result, to come away from home and score four goals is pleasing.
"I thought for large parts of the game in terms of the performance the quality in it was good. There are a couple of sloppy moments in there that we would like to rectify, we gave up their two opportunities and it could've been avoided but overall when you look at it it puts us in a nice place heading into the second-leg.
"I am delighted for Tony, it is a part of his game that he has improved so much this season but I think if you look at the quality of the goals, we knew it would take a variation and I think that is pleasing to see that it has come from that."
The Gers squad featured a number of young players with 16-year-old Greig Allen and 15-year-old Rory Wilson both coming on as second-half substitutes.
Gilmour continued: "I think when you see Greig coming on at centre-back he did really well in terms of his composure with the ball but he also had a few moments in the box that he had to go and deal with. Also young Rory coming on and going and searching, and it was an opportunity.
"I speak about it all the time there will always be that opportunity regardless of age to go and get some game time and prove the quality they have."
Gilmour says the tie is not over yet as they look to the second-leg in Dumbarton on December 7.
"We will look at it as always but for now it will be parked and we will be focussing on Cove Rangers next Tuesday night. That will become the full focus but when this one swings back around there's a lot to take from it.
"Now we have a good look at each other as well and both teams will be doing that so it will be an interesting one and the tie is very much still there, I know we are in favour at the moment but the tie is certainly not put to bed."
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