what is the grammar form where 找 is used twice in the sentence 林先生找工作找了多长时间? I'm learning Chinese by studying Zhongwen Red (中文 Red).
I've come across the following sentence: 林先生找工作找了多长时间?  This sentence is from http://www.zhongwenred.com/R67.html.
This webpage spaces out the words and translates it like the following:

林 先生 找 工作 找了 多长时间?
Lín xiānsheng zhǎo gōngzuò zhǎole duō cháng shíjiān?
For how long has Mr. Lin been looking for work?

I'm wondering what the grammatical construct 找 工作 找了 means.  Is the general format verb1 object verb2 了?
I have a couple questions about this:

What are some examples of sentences in this same format?
In verb1 object verb2 了, do both verb1 and verb2 have to be the same verb?  If not, could you give some example sentences where they are not the same verb?
Does this construct need to be followed some word like 多长时间?
Does this have any relation to reduplication of verbs?
Does this grammar form have any meaning without the 了 after verb2?
Though I don't believe it is necessary for the example sentence you gave, there are cases where you're required to repeat the verb. I'd just post this as a comment if I could but I think this image sums it up nicely:
https://resources.allsetlearning.com/chinese/grammar/degree_complement