Sri Vishal Agarwal-ji suggests the following:
For Mandala 2, 3 and 7: Dr Velankar's translations. His Mandala 5 translation was also published posthumously by his student Dr. Moghe. Additionally, Dr. Velankar translated the Indra and Agni hymns of the entire Rigveda (including Mandalas 8,10, with Mandala 9 become Pavamana Suktas) in scattered journal articles. Likewise, Ribhu, Ashwin and other Deities' hymns were translated by K P Jog, V G Davane and other scholars (I have hard copies or for some also soft copies). Copies of Mandalas 2-3 translations are very difficult to get (I had someone photocopy from an original at the Bombay University Library around 15 years back).
For Mandala 9, Suktas 1-72, there is a great commentary by Dr S S Bhawe in 3 slim volumes, which elicited quite a racist comment by F B J Kuiper (Witzel's teacher).
All the above relate to the Shakala Shakha of RV, and meanwhile two other Shakhas have been printed - Ashwalayana by B B Chaubey wherein he has translated the 250 odd new Mantras that are found; and the Shankhayana Shakha Samhita by Amal Dhari Singh, wherein again we find numerous new mantras (most of them also in the former) but he has not given a translation of the newer ones. For the Shankhayana Praisha Adhyaya, the only option is
Priesthood in ancient India : a study of the Maitravaruna priest
For Suparnadhyaya (Rigveda Khila, some Suktas found in Shankhayana Samhita), refer:
Śrī Suparṇādhyāyaḥ : R̥gvedīyakhilātmakaṃ kāvyarūpakam: padapāṭhasaṃvalitaḥ Śrījayasvāmikr̥tabhāṣyopetaśca
New Delhi : National Mission for Manuscripts and DK Printworld, 2016.
Many other new mantras in Shankhayana Samhita also translated in the following:
Atha R̥gvedīya-Śāṅkhāyana-Rudrādhyāyaḥ
Prakash Pandeya; IGNCA, DK Printworld: 2009
For all the Rigvedic Khilas, the following with a translation:
Usha Bhise. 1995. The Khila Suktas of the Rgveda A Study. BORI: Pune