Sentence Structure - Verb vs Noun Usage

Question

I have been actively learning to write English for over a month. Though I can, some how, manage with grammar, sentence structures are not easy for me. In the sentence below, please any one comment why this usage is not correct or it is.

Original: " De Mestral patented Velcro in 1955, subsequently refining and developing its practical manufacture until its commercial introduction in the late 1950s "

Modified : " De Mestral patented Velcro in 1955, subsequently refining and developing its practical manufacture until it was commercially introduced in the late 1950s "

Also, please answer which is the most preferred one in the written English and why ?

Answer 1

The two sentences are correct. Because here after until we are expecting an event, "until what?", so here the two sentences express the event of the commercial introduction of the manufacture.

So here its commercial introduction and it was commercially introduced are similar and describe the wanted event in two different ways.

But the first one is more appropriate because referring to the until/till section here after until we usually expect a noun:

Structure: Until, till:

until/till + noun describing time/date: examples: next week, this evening, tomorrow.

e.g. Tom's wife will stay here until/till the end of next week.

Until/till the end of the month, you can use my computer.