1. There are four Arun Samhits available from Arun Publications, Chandigarh. It is not mentioned which Arun Samhita is translation of which edition of Lal Kitab. Details are as follows -

I. Arun Samhita (Lal Kitab) Jyotish,  Translation of 1952 Edition
II. Arun Samhita (Lal Kitab) Hast Rekha Vigyan
III. Arun Samhita (Lal Kitab) Samudrik
IV. Arun Samhita (Lal Kitab) Chaturth Bhag. Translation of 1939 Edition

1952 edition of Arun Samhita Jyotish is more than sufficient to start with. 1952 edition is well translated but not that well proofread.  But remember beggars are not choosers. It is direct translation (rather transliteration - only change of script) from Urdu, it is quite close to the original Urdu edition. For example here you can apply your own mind, if you have basic knowledge of Hindi. Quality of other Arun Samhitas is even worse but again you don’t have many options other than to apply your own common sense.

2. As mention in English section, Hindi version of Lal Kitab (The Exposition & Background) is also available in market by the name of "Lal Kitab (Prishthaboomi aur Vyakhya). As options are available in Hindi.

Other than above two options, highly priced photocopies of Hindi translations are also being sold in market claiming the 'original translation' in Photostat format. Whatever written on these photocopy editions due to misprints and errors. Please go for them on your own risk.