Definite signs of progress BiB and take it as a good sign you're getting stronger at a lean bodyweight, you don't need to be 200lbs+ to be physically impressive so don't be in any rush to gain weight.
Someone recently made the comment to me that a calorie surplus of 100 or 1000 will both be fine, as long as you are indeed getting that surplus. The latter will of course result in more weight gain but it may not all be muscle. So again don't be in any major rush, I would look for as slow as 1lbs a week for a few months then perhaps more like 1lb every 2 weeks.
Lastly with those numbers at that bodyweight, you may well have some decent Powerlifting potential