Some of the ships from Alex Milne’s Hot Motor Oil.
For those curious, here’s a list of all the pairs in the booklet: Perceptor x Brainstorm, Drift x Rodimus, Starscream x Windblade, Arcee x Aileron, Rodimus x Megatron, Starscream x Megatron, Soundwave x Megatron [opposing pages, no less!], Megatron x Optimus, Tailgate x Cyclonus, some tentacly chick x Bee, Elita x Optimus, Pharma x Ratchet, Anode x Lug, Chromedome x Rewind, Chromia x Ironhide, Starscream x Bee, Magnus x Megatron, Pharma x Tarn, Ratchet x Drift, Soundwave x Cosmos
To me, the only noticeable one missing is Rodimus x Magnus