Peel Hunt has upgraded FTSE 100 industrial engineer Weir from hold to buy following yesterday's acquisition of Seaboard Holdings.Weir, which operates in the oil, gas, power and mineral markets, announced that it would pay $675m for US wellhead specialist Seaboard, a deal which Peel Hunt thinks looks "highly complementary" to products in Weir's oil and gas division. "Even though the valuation looks full, it comes with good growth and cross-selling potential", the broker said.The rating upgrade comes as the shares have de-rated, but as the broker values the company at a 20% premium to the sector average, the target price is reduced from 2,100p to 2,000p.Galvan Research has given packaging company Rexam a buy rating, saying that the FTSE 100 firm is a "canny investment".Galvan says that a combination of factors - including an upbeat 2012 outlook, a decent charting picture and the possibility that the underperforming Personal Care division could be divested - mark the shares out as a buy."The upside for Rexam should be the current position of the 200-day moving average at 360p," said Galvan's head of research Andrew Gibson.Evolution Securities has downgraded its rating on West Africa-focused oil and gas exploration group BowLeven from buy to neutral, saying that the latest results from Sapele-3 well "leaves more questions than answers".The firm announced on Thursday that the well, located off the coast of Cameroon, found 8m of net hydrocarbon pay of which 6m were located in reservoir sands with good porosity and permeability. However, Evolution notes that "only mud log analysis and gas chromatography were used to indicate that the sands are likely to be oil bearing."Analyst Richard Griffith says that this is "far from conclusive" and investors will not know the well's true potential until the appraisal programme in 2012. The broker cuts its target price from 190p to just 80p and downgrades but notes that this is more to do with timing issues rather than potential.BC